Logical Positivism

THE LIBRARY OF PHILOSOPHICAL MOVEMENTS
GENERAL EDITOR: Paul Edwards

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printing number

5 6 7 8 9 10

Preface

U,0cal is fte » a » ™U

available to the general p viewooints. Each volume will deal

of philosophers of J'Jg two philosophical “schools” or

with one or, m some cases, wi ’ rarely umted by

“movements.” It is inspires political or religious

the kind of common purpose ^ jul to consider the

“movements.” Nevertheless, it frequen^ similarities in their aim
work o. different iSi has beer, adopted in dc-

SiSr ii“»r, f^-^'tSTEngiish, many o£ the

~ Ste

These and other amcte “«am jrtonlan™^^

doctrines most /®^°“pJotessor .^ver in his introduction,

ever, for reasons explained by as 'expositions or defenses

several pieces whmh canno gj ^ included. The scope of the

of logical positivism have also oeen ^ would sug-

bibliography, too, b broa^r than ho philosophy . a

gest. No volume dealing with ot therefore thought desirable

contemplated in this ^^^"cs and it was t^

to Ust L S 4lT„i po-dvism.

of analytic philosophy the translators who gen-

I wish to express my Ifahwoe _
erously contributed their labOT^t^ M helping to com-

Irving Salt 2 inann, and Satinoff, Maxwell Grober, and

pile the bibliography, and to L^on

L6 Huerta-Jourda for Pf P^^n^ ^ notes which indi-

to Professors Carnap and He p papers,

cate their present PO^iPon on translation

Professor Carnap was also kind enou^n

of his own articles. p^UL Edwards

Preface

Editor’s Introduction

Logical Atomism

1. Bertrand Russell

“Logical Atomism”

Philosophy, Metaphysics and Meaning

2. Moritz Schlick

“Tme Turning Point in Philosophy”

5. Rudolf Carnap

“The Elimination of Metaphysics through
Logical Analysis of Language”

4. Moritz Schlick

“Positivism and Realism”

5. Carl G. Hempel

“The Empiricist Criterion of Meaning”

Logic and Mathematics

6. Rudolf Carnap

“The Old and the New Logic”

7. Hans Hahn

“Logic, Mathematics and
Knowledge of Nature”

Contents

[viii]

* Knowledge and T ruth

8. Rudolf Carnap

“Psychology in Physical Language” 165

9. Otto Neurath

“Protocol Sentences” 199

10. Moritz Schlick

“The Foundation of Knowledge” 209

11. A. J. Ayer

“Verification and Experience” 228

Ethics and Sociology

12. Moritz Schlick

“What Is the Aim of Ethics?” 247

13. C. L. Stevenson

“The Emotive Meaning of Ethical Terms” 264

14. Otto Neurath ''

“Sociology and Physicalism” 2S2

Analytical Philosophy

15. Frank D. Ramsey

“Philosophy” 321

16. Gilbert Ryle

“Philosophical Arguments” 327

17. Friedrich Waismann

“How I See Philosophy” 345

Bibliography of Logical Positivism 381

Index

447

LOGICAL POSITIVISM

Editor s Introduction

I. History of the Logical Positivist Movement

The term ‘‘Logical Positivism” was coined some thirty years ago
to characterize the standpoint of a group of philosophers, scientists
and mathematicians who gave themselves the name of the Vienna
Circle. Since that time its reference has been extended to cover j

other forms of analytical philosophy; so that disciples of Bertrand
Russell, G. E. Moore or Ludwig Wittgenstein at Cambridge, or
members of the contemporary Oxford movement of linguistic analysis
may also find themselves described as logical positivists. This wider
usage is especially favored by those who are hostile to the whole
modern development of philosophy as an analytical rather than a i

speculative enquii^'. They wish to tar all their adversaries with a ;

single brush. This is irritating to the analysts themselves who are (
rather more sensitive to their differences; they would prefer that the
appellation of “logical positivist” be reserved for those wLo share the 5
special outlook of the Vienna Circle. In compiling this anthology, I
have not been quite so strict. I have drawn mainly on the writings •
of the members of the Vienna Circle, or of those who stand closest
to them, but I have also included wSeveral pieces which fall outside i
this range. They are ail, in some sense, analytical but the scope of
what I regard as analytical philosophy is wide. It allows for serious ;

disagreement, not only over technical niceties, but on major points !

of doctrine, including the method and purpose of analysis itself. I

The Vienna Circle came into being in the early 1920’s when ,

Moritz Schlick, around whom it centered, arrived from Kiel to be« ^

come professor of philosophy at the University of Vienna. On the j

philosophical side its leading members, besides Schlick himself, j

were Rudolf Carnap, Otto Neurath, Herbert Feigl, Friedrich Wais- t

mann, Edgar Zilsel and Victor Kraft; on the scientific and mathe« |

matical side, Philipp Frank, Karl Menger, Kurt G5del and Hans
Hahn. At the beginning, it was more of a club than an organized
movement. Finding that they had a common interest in, and a 1

[33

[ ] Editor's Introduction

similar approach to, a certain set of problems, its members met
regularly to discuss them. These meetings continued throughout the
life of the Circle but they came to be supplemented by other activi-
ties which transformed the club into something more nearly resem-
bling a political party. This process began in 1929 with the publi-
cation of a manifesto entitled “Wissenschaftliche Weltauffassung,
Der Wiener Kreis” — The Vienna Circle; Its Scientific Outlook —
which gave a brief account of the philosophical position of the group
and a review of the problems in the philosophy of mathematics and
of the physical and social sciences that they were chiefly concerned
to solve. This pamphlet, which was written by Carnap, Neurath and
Hahn, is also of interest as showing how the Circle situated itself
in the history of philosophy. After claiming that they were developing
a Viennese tradition which had flowered at the end of the nineteenth
century in the work of such men as the physicists Ernst Mach and
Ludwig Boltzmann, and, in spite of his theological interests, the
philosopher Franz Brentano, the authors set out a list of those
Ihey regarded as their main precursors. As empiricists and
positivists they named Hume, the philosophers of the enlightenment,
Comte, Mill, Avenarius and Mach; as philosophers of science, Helm-
holtz, Riemann, Mach, Poincare, Enriques, Duhem, Boltzmapn and
Einstein; as pure and applied logicians, Leibniz, Peano, Frege,
Schrdder, Russell, Whitehead and Wittgenstein; as axiomatists, Pasch,
Peano, Vailati, Fieri and Hilbert; and as moralists and sociologists
of a positivistic temper, Epicurus, Hume, Bentham, Mill, Comte,*
Spencer, Feuerbach, Marx, Miiller-Lyer, Popper-Lynkeus and the
elder Carl Menger. This list is surprisingly comprehensive, but it
must be remembered that in most cases it is only a question of a
special aspect of the author’s works. Thus Leibniz is included for
his logic, not for his metaphysics; Karl Marx is included neither for
his logic nor his metaphysics but for his scientific approach to history.
If we exclude contemporaries from the list, those who stand closest
to the Vienna Circle in their general outlook are Hume and Mach. It
is indeed remarkable how much of the doctrine that is now thought
to be especially characteristic of logical positivism was already
stated, or at least foreshadowed, by Hume.

Among contemporaries, Einstein, Russell, and Wittgenstein are
singled out by the authors of the pamphlet for their kinship to the
Vienna Circle and the extent of their influence upon it. Wittgenstein,
indeed, stood to the Vienna Circle in a special relation. Having
been a pupil of Russell’s at Cambridge before the first world war
he returned to Vienna and was there when his Logisch-Philosophische

Editor's Introduction [ 5 ]

Abhandlung was published in 1921. This famous book, which is
better known as Tractatus Logico-Philosophicus, the title given to
its English translation, had an enormous effect upon the positivist
movement, both in Vienna and elsewhere. It would not be quite
correct to say that the Vienna Circle drew its inspiration from it.
Schlick himself, in his book on the theory of knowledge, Allgemeine
Erkenntnislehre, of which the first edition appeared in 1918, had
independently arrived at a similar conception of philosophy; and there
is a hint of mysticism in the Tractatus w^hich some members of the
Circle, especially Neurath, found disquieting; but as a whole they ac-
cepted it, and it stood out as the most powerful and exciting, though
not indeed the most lucid, exposition of their point of view. Wittgen-
stein did not ofiicially adhere to the Circle but he maintained close
personal relations at least with Schlick and Waismann whom he con-
tinued to influence even after his departure for Cambridge in 1929.
In Cambridge, where he taught until 1947, four years before his
death, he exercised an almost despotic sway over his pupils, and
though he published nothing during these years except one short
article his influence was strongly, if in most cases indirectly, felt by
almost all the younger generation of British philosophers. He himself
modified the rigors of his early positivism to an extent that can be
measured by comparing the Tractatus with his posthumously pub-
lished Philosophical Investigations; and it is to his influence, com-
bined with that of Moore, that one may largely attribute the pre-
occupation of contemporar}^ British philosophers with the everyday
uses of language, and their tendency to deal with philosophical ques-
tions in an unsystematic, illustrative way, in contrast to the more
rigorous would-be scientific method which was favored by the Vienna
Circle. This is one reason w’hy they are not happy to be described
as Logical Positivists. But I shall have more to say about these alter-
native conceptions of analysis later on.

It was in 1929 also that the Vienna Circle organized its first in-
ternational congress. It was held at Prague and was followed at inter-
vals throughout the thirties by further congresses at Konigsberg,
Copenhagen, Prague, Paris and Cambridge. These meetings furthered
the ambition of the Circle to develop Logical Positivism as an inter-
national movement. It had formed an early alliance with the so-called
Berlin school of which Hans Reichenbach, Richard von Mises, Kurt
Grelling and at a later date Carl Hempel were the leading members.
The congresses helped it to make contact also with Scandinavian
philosophers such as Eino Kaila, Arne Naess, Ake Petzall, Joergen
Joergensen, and the Uppsala school of empiricists, with the Dutch

[ 6 ] Editor’s Introduction

group around the philosopher Mannoury who pursued what they
called the study of Signifies, with the Munster group of logicians
under Heinrich Scholtz, with American sympathizers such as Nagel,
Charles Morris and Quine, and with British analysts of various shades
of opinion, such as Susan Stebbing, Gilbert Ryle, R. B. Braithwaite,
John Wisdom and myself. The brilliant Cambridge philosopher F. P.
Ramsey was marked as an adherent, but he died in 1930 at the early
age of 26. An alliance was also formed with the very important Polish
groups of philosophers and logicians, of whom Lucasiewicz, Les-
nievsky, Chwistek, Kotarbinski, Ajduciewicz and Tarski were per-
haps the most prominent. The influence of Tarski’s work, particularly
on Carnap, was noticeably strong.

The missionary spirit of the Circle found a further outlet in its
publications. In 1930 it took over a journal called Annalen der
Philosophie, renamed it Erkenninis and made it, under the editorship
of Carnap and Reichenbach, the principal organ of the positivist
movement. In the following years there also appeared a series of
monographs with the collective title of Einheitswissenschaft — Unified
Science — and a series of books, under the general editorship of
Schlick and Philipp Frank, with the collective title of Schriften zur
Wissenschaftliche Weltauffassung. Schlick himself contributed to it a
book on ethics, of which the first chapter is included in this volume,
and Frank a book on the law of causality and its limitations. Among
the other volumes to appear in it were an important book by Carnap
on the logical syntax of language, to which I shall have occasion to
refer again, a book on sociology by Neurath with somewhat Marxist
leanings, and Karl Popper’s famous Logik der Forschung which was
devoted to the philosophy of science. Popper was not in fact a mem-
ber of the Circle and would at no time have wished to be classed as
a positivist, but the affinities between him and tlie positivists whom
he criticized appear more striking than the divergencies. In any case
the members of the Circle did not in all points agree among them-
selves.

Though the logical positivist movement gathered strength through-
out the thirties, the Vienna Circle itself was in the process of dissolu-
tion. By 1933, when I attended its meetings, Carnap and Frank had
accepted chairs at the University of Prague and the discussions were
chiefly carried on by Schlick, Neurath, Waismann and Hahn. But
Hahn died in 1934 and two years later Schlick was murdered, at the
age of 54, by a demented student who shot him as he was entering
the University. The hostile tone of the obituaries which were devoted
to Schlick in the governmental press, implying almost that logical

Editofs Introduction [ 7 ]

positivists deserved to be murdered by their pupils, foreshadowed
the troubles which were soon to fall upon the Circle, Except for
Neurath, who had participated in the revolutionary Spaitacist Gov-
emment in Munich at the end of the first world war, its members had
not been conspicuously active in politics, but their critical and
scientific temper made them suspect to the right-wing clerical govern-
ments of Dolfuss and Schuschnigg and still more so to the Nazis. The
majority of them were forced into exile. The advent of Nazism was
fatd also to the Berlin school, and the Polish groups were disrupted
by the war. Neurath, who had taken refuge in Holland, made a valiant
attempt to keep the movement going. The title of Erkenntnis was
changed to The Journal of Unified Science and its place of publica-
tion to the Hague. Arrangements were made for the publication by
the University of Chicago, where Carnap was established, of a series
of brochures ambitiously entitled the International Encyclopedia of
Unified Science, Further congresses were planned. But with the out-
break of war and Neurath’s death in England some years later, the
movement lost its cohesion. Most of the volumes which were designed
to constitute the Encyclopedia have in fact appeared, but the Journal
of Unified Science very soon ceased publication and has not been
revived. Besides Carnap, Feigl, Godel, Frank, Hempel and Tarski are
still at universities in the United States, and Waismann and Popper
at universities in England. Scholtz has remained at Munster and
Kotarbinski and Ajduciewicz in Poland; and Victor Kraft resumed
his chair of philosophy at the University of Vienna. But, however
much influence these philosophers may exert individually, they do
not constitute a school In this sense, the logical positivist movement
has been broken up.

Nevertheless its tradition has been continued, especially in Eng-'
land, Scandinavia and the United States. In Scandinavia, Kaila has
been joined at Helsinki by Von Wright, a pupil of Wittgenstein's who
succeeded him for a time as professor of philosophy at Cambridge,
the Uppsala school still flourishes, under the direction of Hedenius,
Segerstedt and Marc-Wogau, v,ith support from the logician
Wedberg in Stockholm, and Ame Naess in Oslo pursues his sociologi-
cal researches into the current uses of language. Petzall continued
to teach at Lund until his death in 1957 and Joergensen is still teach-
ing in Copenhagen, though his positivism has been modified by an
injection of Marxism. In the United States a number of philosophers
like Quine, Nagel and Nelson Goodman conduct logical analysis in
a systematic scientific spirit that is probably closer to the original ideal
of the Vienna Circle than anything that is now to be met with else-

[ 8 ] Editor's Introduction

where. In this connection Nelson Goodman’s book The Structure of
Appearance (1951) and Quine’s collection of essays From a Logical
Point of View (1953) are especially notable. Their active interest in
symbolic logic brings Quine and Goodman also into relation with
Tarski, Godel, Church and other members of the important con-
temporary group of American logicians. The same outlook is main-
tained by Carnap and his pupils, notably Bar Hillel, who is now
teaching at the University of Jerusalem, and by Feigl and Hempel.
Other philosophers in the United States such as Norman Malcolm,
Max Black, Morris Lazerowitz and C. L. Stevenson owe more to
the influence of G. E. Moore or the later Wittgenstein, and conse-
quently display an approach to philosophical questions which is
closer to that of the contemporary British schools.

In spite of the example of Bertrand Russell, there is not now
among British philosophers the same interest in formal logic, or
belief in the utility of symbolic techniques for clarifying philosophical
issues, as is to be found in the United States. Neitlier is there the
same desire to connect philosophy with science. My own Language,
Truth and Logic, of which the first edition appeared in 1936, did
something to popularize what may be called the classical position of
the Vienna Circle; but since the war the prevailing tendency in Eng-
land has been to replace this uncompromising positivism wdth its
blanket rejection of metaphysics, its respect for scientific method,
its assumption that in so far as philosophical problems are genuine
at all they can be definitely solved by logical analysis, by an approach
to philosophy which is empirical in the political sense, tiie sense in
which Burke was a champion of empiricism. Generalizations are dis-
trusted, particular examples are multiplied and carefully dissected.
An attempt is made to illuminate ever>^ facet of a problem rather than
to hammer or carve out a solution, common sense reigns as a con-
stitutional, if not an absolute, monarch, philosophical theories are
put to tlie touchstone of the way in which words are actually used.
The metaphysician is treated no longer as a criminal but as a patient:
there may be good reasons why he says the strange things that he
does. This therapeutic technique, as it has been called, is well dis-
played in the work of John Wisdom, now a professor at Cambridge,
whose collected volumes of articles. Other Minds and Philosophy and
Psycho-Analysis, appeared in 1952 and 1953. A more robust form
of therapy is practised by Gilbert Ryle, professor of metaphysics
at Oxford, whose Concept of Mind (1949), with its attack on the
Cartesian myth of “the ghost in the machine,” has had a very great

Editors Introduction [ 9 ]

influence. Ryle shares with Wisdom a taste, and a gift, for analogy
and metaphor, and a fondness for piling up examples, but he is less
afraid of a generalization, less tolerant of departures from ordin^
usage^ more direct in Ms method than any present-day Wittgenstein-
ian, and more ready to assume that a philosophical problem has a
correct solution. What is now sometimes called the Oxford school,
wMcii takes its tone from J. L. Austin more than from Ryle, carries its
interest in the ordinary use of language to a point where it may be
thought that philosophical analysis has given way to the study of
philology. But this tendency is not all-prevailing. The work of such
philosophers as Stuart Hampshire, P. F. Strawson and David Pears
shows diat even within the framework of the Oxford manner there is
still room for a fairly wide latitude of approach. The charge of
scholasticism which is brought against “Oxford philosophy” is not
entirely baseless; but it is not a truly warranted indictment.

At the present time, the philosophical world is curiously divided.
If positivism be taken in its widest sense, the sense in which it em-
braces all shades of analytical, linguistic, or radically empirical
philosophy, it is dominant in England and in Scandinavia, and com-
mands considerable allegiance in Holland and Belgium, in Australia
and in the United States. Elsewhere, it makes hardly any showing at
all. Theoretically, it is not in all respects at odds with Marxism: the
two at least have certain enemies in common: but it cannot flourish
under Communist reginies, since Lenin's Materialism ami Empirio-
Criticism, an attack on Mach and his followers which appeared in
1905, declares it to be a form of bourgeois idealism. In other coun-
tries again, one finds philosophers subscribing to neo-Thomism or to
neo-Kantianism or to neo-Hegelianism or to Existentialism or what-
ever form of German metaphysics may be in fa.shion. The ascend-
ancy of Germany over France in this respect is especially remarkable.
Conversely, in English-speaking countries there has been throughout
the present century an almost complete disregard of the current
extravagancies of German speculative thought. Such national divisions
are indeed regrettable. They do not occur to anything like the same
extent in other branches of learning. It is especially characteristic of
philosophers that they tend to disagree not merely about the solution
of certain problems but about the very nature of their subject and the
methods by which it is to be pursued. Like others before them, the
Vienna Circle believed that this could and should be remedied. They
thought that they had succeeded, where Kant bad failed, in finding a
way “to set philosophy upon the sure path of a science.” This end

[ 10 ] Edito/s Introduction

has not been attained: it may, indeed, be unattainable. All the same,
there can be progress in philosophy and in one way and another the
positivist movement is achieving it.

II. The Attack on Metaphysics

‘‘When we run over libraries, persuaded of these principles, what
havoc must we make? If we take in our hand any volume; of divinity
or school metaphysics, for instance; let us ask, Does it contain any
abstract reasoning concerning quantity or number? No. Does it con-
tain any experimental reasoning concerning matter of fact and exist-
ence? No. Commit it then to the flames: for it can contain nothing but
sophistry and illusion.” This quotation is taken from David Hume's
Enquiry Concerning Human Understanding. It is an excellent state-
ment of the positivist’s position. In the case of the logical positivists,
the epithet “logical” was added because they wished to annex the dis-
coveries of modern logic; they believed, in particular, that the logical
symbolism which had been developed by Frege, Peano and Russell
would be serviceable to them. But their general outlook was very
much the same as Hume’s. Like him, they divided significant proposi-
tions into two classes; formal propositions, like those of logic or pure
mathematics, which they held to be tautological, in a sense that I
shall presently explain, and factual propositions, of which it was re-
quired that they should be empirically verifiable. These classes were
supposed to be exhaustive: so that if a sentence succeeded neither
in expressing something that was formally true or false nor in express-v
ing something that could be empirically tested, the view taken was
that it did not express any proposition at all. It might have emotive
meaning but it was literally nonsensical. A great deal of philosophical
talk was held to fall into this category: talk about the absolute, or
transcendent entities, or substance, or the destiny of man. Such
utterances were said to be metaphysical; and the conclusion drawn
was that if philosophy was to constitute a genuine branch of know-
ledge it must emancipate itself from metaphysics. The Viennese
positivists did not go so far as to say that all metaphysical works
deserved to be committed to the flames: they allowed, somewhat per-
functorily, that such writing might have poetic merit or even that it
nnght express an exciting or interesting attitude to life. Their point
was that even so it did not state anything that was either true or false
and consequently that it could contribute nothing to the increase of
knowledge. Metaphysical utterances were condemned not for being
emotive, which could hardly be considered as objectionable in itself,
but for pretending to be cognitive, for masquerading as something

Editofs Introduction [ ]

that they were not. Attacks on metaphysics occur fairly frequently
in the history of philosophy. I have quoted Hume and I might also
have quoted Kant who mamtained that the human understanding lost
itself in contradictions when it ventured beyond the bounds of pos-
sible experience. The originality of the logical positivists lay in their
making the impossibility of metaphysics depend not upon the nature
of what could be known but upon the nature of what could be said.
Their charge against the metaphysician was that he breaks the rules
which any utterance must satisfy if it is to be literally significant.

At the outset, their formulation of these rules was linked with
a conception of language which Wittgenstein, who inherited it from
Russell, made fully explicit in his Tractatus. The underlying assump-
tion is that there are statements which are elementary in the sense
that, if they are true, they correspond to absolutely simple facts.
It may be that the language which we actually use does not contain
the means of expressing these statements: the statements which it
can serve to express may none of them be entirely elementary; but
these more complex statements must still rest upon a foundation of
elementary statements, even if the foundation be hidden. They are
significant only in so far as they say what would be said by affirming
certain elementary statements and denying certain others, that is, only
in so far as they give a true or false picture of the ultimate ‘‘atomic”
facts. They can, therefore, be represented as being constructed out
of elementary statements by the logical operations of conjunction
and negation, in such a way that their tmth or falsehood is entirely
dependent on the truth or falsehood of the elementary statements in
question. Thus, assuming p and q to be elementary statements, the
“molecular” statement “p or q” is taken to be equivalent to “not
(not-/; and not-r/)”; and this means that it is false if both p and q are
false, but true in the three remaining cases, namely that in which
p and q are both true, that in wffiich p is true and q false, and that in
which p is false and q tme. In general, given n elementary statements,
where ti is any finite number, there are 2” possible distributions of
truth and falsehood among them: and the meaning of the more com-
plex statements which can be constructed out of them is constituted
by the selection of truth distributions with which they agree or
disagree.

As a rule, it will be found that a statement agrees with some truth
distributions and disagrees with others: among the possible states
of affairs with which it is concerned, some would make it true, and
others would make it false. There are, however, two extreme cases;
that in which a statement agrees with every truth distribution and

[ ^2 ] Editor's Introduction

that in which it agrees with none. In the former case it is true in any
circumstances whatsoever, and in the latter case false. According to
Wittgenstein, these two extremes are those of tautology and contra-
diction. On this view, all the truths of logic are tautologies; and if
Russell and Whitehead succeeded in their attempt to show that mathe-
matics is reducible to logic, so are the truths of mathematics. Witt-
genstein himself did not allow that mathematical statements were
tautologies; he said that they were identities: but apart from technical
considerations, this comes to much the same thing. The point is that
neither say anything about the world. The only way in which they
can add to our knowledge is by enabling us to derive one statement
from another: that is, by bringing out the implications of what, in a
sense, we know already.

Tautologies say nothing because of their excessive modesty: since
they agree with every possible state of affairs, they make no claim
upon the facts. Thus, I obtain some information, whether true or
false, about the habits of lions if I am told that they are carnivorous,
and equally if I am told that they are not; but to tell me that they are
either carnivorous or not is to tell me nothing about them at all.
Similarly, contradictions say nothing because of their excessive can-
tankerousness; to disagree with every possible state of affairs is again
to be disqualified from giving any information. I learn nothing, not
even anything false, about the habits of lions if I am told that they
are and are not carnivorous. On this interpretation, tautologies and
contradictions are degenerate cases of factual statements. Meta-;
physical assertions, on the other hand, are meaningless because they
bear no relation to fact. They are not constructed out of elementary
statements in any way at all.

Since Wittgenstein did not say what he took his elementary
statements to be, he did not make it quite clear at what point one
is deemed to enter into metaphysics. It would seem, however, that
any attempt to characterize reality as a whole, any such assertion as
that the Universe is spiritual, or that everything happens for the
best in the best of all possible worlds, must for him be metaphysical;
for such assertions do not discriminate between possible states of
affairs within the world — no matter what happens, it is to be char-
acterized as spiritual, or regarded as happening for the best — ^from
which it follows that they are not factual. Neither do they seem to
be constructed out of factual statements in the way that tautologies
are. And even if they were they would still say nothing.

Whatever may have been Wittgenstein’s own view, his followers
took it for granted that the elementary statements which yielded this

Editor's Introduction . [ ]

criterion of meaning were reports of observations. As we ^all see
later on, they soon came to disagree about the character of these
reports. There was a dispute over the question whether they were
infallible, and whether they referred to the private sensations of the
speaker, or to public physical events. But it was agreed that, in one
form or another, they provided the touchstone by reference to which
all other statements were empirically verified. And since, according
to Wittgenstein’s theory, they alone furnished these statements with
their factual content, they were also responsible for their meaning.
This view was then summed up in the famous slogan that the meaning
of a proposition is its method of verification.

The assumption behind this slogan was that everything that could
be said at all could be expressed in terms of elementary statements.
All statements of a higher order, including the most abstract scientific
hypotheses, were in the end nothing more than shorthand descriptions
of observable events. But this assumption was very difficult to sus-
tain. It was particularly vulnerable when the elementary statements
were taken to be records of the subject’s immediate experiences: for
while it has sometimes been maintained that statements about physical
objects can be faithfully translated into statements about sense-data,
no such translation has ever been achieved: there are, indeed, good
grounds for supposing that it is not feasible. Moreover this choice of
a basis raised the question of solipsism; the problem of making the
transition from the subject’s private experiences to the experiences of
others and to the public world. Carnap, indeed, in his Der logische
Aufbau der Welt (1928) made a valiant attempt to reconstruct our
whole apparatus of empirical concepts on a solipsistic foundation,
taking as his starting-point the single undefined notion of remembered
similarity: but he later acknowledged that this enterprise did not
succeed. The position was easier for those who treated elementary
statements as descriptions of physical events, though their right to
do this remained in question: they at least were not troubled by the
problem of solipsism or by the difficulty of reducing physical objects
to sense-data. But other difficulties remained. The most serious
of all, perhaps, was presented by the case of universal statements
of law. For while the truth of such a statement may be confirmed
by the accumulation of favorable instances, it is not formally entailed
by them; the possibility that a further instance will refute it must
always remain open: and this means that statements of this sort
are not conclusively verifiable. On the other hand, they can be
conclusively falsified in the sense that a negative instance formally
contradicts them. For this reason Karl Popper suggested in his

[ 14 ] Editor's Introduction

Logik der Forschung that what should be required of a factual
statement was just that it be capable in theory of being falsified.
And he argued that apart from the logical superiority of this cri-
terion it was more in accord with scientific practice; for scientists
set up hypotheses which they test by looking for counter-examples:
when a counter-example is discovered the hypothesis is rejected or
modified; otherwise it is retained. But Popper’s criterion has demerits
of its own. For instance, as he himself recognizes, it allows one to
deny an indefinite existential statement but not to aEBirm it. One
can say that there are no abominable snowmen, for this could be
falsified by finding them, but one cannot say that there are abominable
snowmen, for this could not be falsified; the fact that one had
failed to find any would not prove conclusively that none existed.
What could be disproved would be that any of them existed at a
particular place and time, and it is only if this further specification
is given that the statement becomes legitimate: otherwise it is to
be counted as metaphysical. But this is to bring the frontiers of
metaphysics rather close.

Because of this and other diflSculties the view^ which came to
prevail among the logical positivists was that the demands that a
statement be conclusively verifiable, or that it be conclusively fal-
sifiable, were both too stringent as criteria of meaning. They chose
instead to be satisfied with a weaker criterion by which it was re-
quired only that a statement be capable of being in some degree con-
firmed or disconfirmed by observation; if it were not itself an'
elementar}' statement, it had to be such that elementary statements
could support it, but they did not need to entail it or to entail its
negation. Unfortunately, this notion of “support” or “confirmation”
has never yet been adequately formalized. Various attempts have
been made to give '’the verification principle,” in this weaker form,
a thoroughlv precise expression, but the results have not been alto-
gether satisf actor}'. However, the employment of the principle did
not wait upon its proper formulation; its general purport was held
to be sufficiently clear. I have already given examples of the kind of
philosophical talk that it served to eliminate: but its destructiveness
was not confined to what one might call the grosser forms of meta-
physics. As employed by the Viennese positivists, it made short work
of most of the perennial problems of philosophy. Thus, the questions
at issue between monists and pluralists, or between realists and
idealists, were accounted no less spurious than questions about the
limitations of Being, or a transcendent world of values. For what
empirical test could possibly go to decide whether the world is one

Editofs Introduction [ ]

or many, or whether the things that we perceive do or do not exist
outside someone’s mind? It is characteristic of such rival philo-
sophical theses as realism and idealism that each is consistent with
all the appearances, whatever their content may happen to be. But,
for the positivist, it is just this that condemns them.

An obvious objection to the verification principle, which the
positivists’ opponents were quick to seize on, is that it is not itself
verifiable. I suppose that it might be taken as an empirical hypothesis
about the way in which people actually use the word “meaning,”
but in that case it would appear to be false; for it is not contrary
to ordinary usage to say that metaphysical utterances are meaningful.
Neither did its sponsors put the principle forward as the result of
any such empirical investigation. But then what status did they think
it had? Might it not itself be metaphysical? Surprisingly, Wittgenstein
acceded to this charge. “My propositions,” he said at the end of the
Tractatus, “are elucidatory in this way: he who understands me
finally recognizes them as senseless, when he has climbed out through
them, on them, over them. (He must so to speak throw away tlie
ladder, after he has climbed up on it.) He must surmount these
propositions; then he sees the world rightly.” But this is a vain
attempt to have it both ways. No doubt some pieces of nonsense
are more suggestive than others, but this does not give them any
logical force. If the verification principle really is nonsensical, it
states nothing; and if one holds that it states nothing, then one can-
not also maintain tiiat what it states is true.

The Vienna Circle tended to ignore this difficulty: but it seems
to me fairly clear that what they were in fact doing was to adopt
the verification principle as a convention. They were propounding a
definition of meaning which accorded with common usage in the
sense that it set out the conditions that are in fact satisfied by state-
ments which are regarded as empirically informative. Their treatment
of a priori statements was also intended to provide an account of the
way in which such statements actually function. To this extent tlieir
work was descriptive; it became prescriptive with the suggestion
that only statements of these two kinds should be regarded as either
true or false, and that only statements which were capable of being
either true or false should be regarded as literally meaningful.

But why should this prescription be accepted? The most that
has been proved is that metaphysical statements do not fall into the
same category as the laws of logic, or as scientific hypotheses, or as
historical narratives, or judgments of perception, or any other
common sense descriptions of the “natural” world. Surely it does not

[ 16 ] Edito/s Introduction

follow that they are neither true nor false, still less that they are
nonsensical?

No, it does not follow. Or rather, it does not follow unless
one makes it follow. The question is whether one thinks the difference
between metaphysical and common sense or scientific statements to
be sufficiently sharp for it to be useful to underline it in this way. The
defect of this procedure is that it tends to make one blind to the
interest that metaphysical questions can have. Its merit is that it
removes tlie temptation to look upon the metaphysician as a sort
of scientific overlord. Neither is this a trivial matter. It has far too
often been assumed that the metaphysician was doing the same work
as the scientist, only doing it more profoundly; that he was uncover-
ing a deeper layer of facts. It is therefore important to emphasize that
he is not in this sense describing any facts at all

But then what is he doing? What is the point of saying, like
McTaggart, that time is unreal or, like Berkeley, that physical objects
are ideas in the mind of God or, like Heidegger, that the “nothing
nihilates itself’? It should not be assumed that there is a general
answer to this question, that metaphysicians are always doing the
same sort of thing. One must begin in any case by looking at the
context in which such pronouncements occur. Heidegger’s remark is
a piece of verbiage, but it contributes in its fashion to his ^'develop-
ment of the theme that it is a matter for wonder that the world exists.
“Why is there anything at all,” he asks, “and not rather nothing?”
This is indeed the kind of question that people expect philosophers
to put: it has an air of profundity about it. The trouble is that it
does not admit of any answer. On the face of it, McTaggart’s con-
tention that time is unreal seems hardly more sensible. If taken
literally, as implying that nothing ever happens, it is grotesquely
false. And if it is not to be taken literally, what does it mean? The
answer is to be found by looking at IvfeTaggart's arguments. He shows
himself there to be perplexed by the idea of the passage of time; he
tries to prove that the notion of an event’s being successively future,
present, and past involves a vicious infinite regress. The proof is
invalid, but we can learn something from it. In defending our use
of temporal expressions against McTaggart’s arguments we may reach
a clearer understanding of all that it implies. Berkeley, again, was
concerned to discover what could be meant by saying that physical
objects exist: he convinced himself by plausible arguments that
when we speak of physical objects we can be referring only to collec-
tions of “sensible qualities,” the existence of which consists in their
being perceived; and he then brought in God as the permanent sen-

Editor's Introduction [ ]

sorium which was needed to keep things in being. His arguments can
be withstood; but they do raise important philosophical problems
about the meaning and justification of the statements that we make
about the “external world.”

The Viennese positivists were chiefly interested in the formal and
the natural sciences. They did not identify philosophy with science,
but they believed that it ought to contribute in its own way to the
advance of scientific knowledge. They therefore condemned meta-
physics because it failed to meet this condition. The logical analysts
of to-day are more indulgent. They too are opposed to metaphysics
in so far as it is merely rhapsodical: even in the sphere of ethics
they wish to dissociate philosophy from preaching. But they allow
that the metaphysician may sometimes be seeing the world in a fresh
and interesting way; he may have good reason for being dissatisfied
with our ordinary concepts, or for proposing to revise them. In many
cases no doubt he is the victim of a logical error; but such errors
may be instructive. If philosophical problems arise, as Wittgenstein
thought, because we are led astray by certain features of our lan-
guage, the metaphysician, by his very extravagancies, may also
contribute to their dissolution.

in. Language and Fact

With their elimination of metaphysics, the Viennese positivists
hoped that they had also put the theory of knowledge behind tlieni,
but in this they were deceived. The first source of trouble was the
notion of elementary statements. Both their character and status
became a matter of dispute.

At the outset, as I have said, the prevailing view was that these
statements referred to the subject’s introspectible or sensory experi-
ences. This view was adopted because it seemed to follow from the
equation of the meaning of a statement with the method of its veri-
fication. For in the last resort it is only through someone’s having
some experience that any statement is actually verified. In most cases,
the verification would consist in the perception of some physical
object; but it was held, following Russell and ultimately Berkeley,
that perceiving physical objects was to be analyzed in terras of hav-
ing sensations, or as Russell put it, of sensing sense-data. Though
physical objects might be publicly accessible, sense-data were taken
to be private. There could be no question of our literally sharing one
another’s sense-data, any more than we can literally share one an-
other’s thoughts or images or feelings. The result was that the truth

[ 18 ] Editor's Introduction

of an elemcBtary statement could be directly checked only by the
person to whose experience it referred. And not only was his judg-
ment sovereign; in the most favorable case, it was held to be infallible.
One can indeed be mistaken about the experiences that one is going
to have in the future, or even about those that one has had in the past;
it is not maintained that our memories cannot deceive us: but if one
sets out merely to record an experience that one is actually having,
then, on this view, there is no possibility of error. Since one can lie,
one’s statement may be false; but one cannot be in doubt or mistaken
about its truth. If it is false one knows it to be so. A way in which
this point is sometimes put is by saying that statements of this
kind are “incorrigible.”

This conception of elementary statements was exposed to attack
on various grounds. There were some to whom it seemed that no
empirical statement could be incorrigible, in the sense required. They
were therefore inclined to maintain either that one could be mistaken
about the character of one’s present experience, so that the statements
which purported to record it were fallible like the rest, or that these
“direct records of experience” were not genuine statements, since they
purchased their security at the expense of sacrificing all descriptive
content. But the most serious difficulty lay in the privacy of the
objects to which the elementary statements were supposed to refer. If
each one of us is bound to interpret any statement as bein^ ultimately
a description of his own private experiences, it is hard to see how wb
can ever communicate at all. Even to speak of “each one of us” is to
beg a question; for it would seem that on this view the supposition
that other people exist can have no meaning for me unless I construe
it as a hypothesis about my own observations of them, that is, about
the course of my own actual or possible experiences. It was maintained
by Carnap and others that the solipsism which seemed to be involved
in this position was only methodological; but this was little more than
an avowal of the purity of their intentions. It did nothing to mitigate
the objections to their theory.

At first, it was thought that the difficult}- about communication
could be met by drawing a distinction between the content of ex-
periences and their structure. Content, it was maintained, was incom-
municable. Since other people cannot sense my sense-data, or share
my thoughts or feelings, tiiey cannot verify the statements that I
make about them; neither can I verify the corresponding statements
that they make about their experiences. And if I cannot verify them, I
cannot understand them either. To this extent we inhabit entirely
dijfferent worlds. What can be verified, however, is that these worlds

Editor's Introduction [ ]

have a similar structure. I have no means of telling that the feeling
which another person records when he says that he is in pain is at
all like the feeling that I call pain; I have no means of telling that
the colors which he identifies by the use of certain words look at all
the same to him as the colors for which I use these words look to me.
But at least I can observe that we apply the words on the same occa-
sions, that his classification of objects according to their color coin-
cides with mine; I can observe that when he says he is in pain he
displays what I regard as the appropriate signs. And this is all that
is required for communication. It does not matter to me what my
neighbour’s experiences actually are; for all that I can ever know they
are utterly different from mine. What matters is that tlie structure of
our respective worlds is sufficiently alike for me to be able to rely on
the information that he gives me. And it is in this sense only that we
have a common language; we have, as it were, the same canvas which
each of us paints in his own private fashion. It follows that if there
are propositions, like the propositions of science, which have an
inter-subjective meaning, they must be interpreted as descriptions of
structure.

As I have already remarked, the fundamental objection to this
view is that it inconsistently puts the '‘private worlds” of other people
on a level with one’s own; it results in a curious, and indeed contra-
dictory, theory of multiple solipsism. But, apart from this, the dis-
tinction which it tries to make between content and structure does
not seem to be tenable. For what would be an example of a statement
which referred only to structure? There is an echo here of Locke’s
“primai7 qualities.” But statements which refer to the “geometrical”
properties of objects, to “figure, extension, number and motion” have
to be interpreted in terms of content, just as much as statements which
refer to colors and sounds. If I have no means of knowing that my
neighbor means the same as I do by his use of color-words, I have
equally no means of knowing that he means the same by his use of
words which refer to spatial relations or to numerical quantities. I
cannot tell even that what I take to be the same word really is the
same for him. All that I am left with is the apparent harmony of our
behavior. Moreover it seems that the attempt to draw a distinction
within the boundaries of descriptive language between what can and
cannot be communicated must be self-defeating. It leads to the
absurdity to which Ramsey draws attention in his short paper on
“Philosophy,” which is included in this volume: “the position of the
child in the following dialogue: ‘Say breakfast.’ ‘Can’t.’ ‘What can’t
you say?’ ‘Can’t say breakfast.’ ”

[ 20 ] Editor's Introduction

Because of such difficulties, Neurath, and subsequently Carnap,
rejected this whole conception of elementary statements. They argued
that if elementary statements were to serve as the basis for the inter-
subjective statements of science, they must themselves be inter-
subjective. They must refer, not to private incommunicable experi-
ences, but to public physical events. More generally, statements which
ostensibly refer to experiences, or to “mental” states or processes of
any kind, whether one’s own or anybody else’s, must all be equiva-
lent to “physical statements”: for it is only in this way that they
can be publicly intelligible. This is the thesis of physicalism. I shall
not dwell upon it here, as I have inserted an article by Carnap,
“Psychology in Physical Language,” which sets it out at length.

The view that they were included in “the physical language” took
away from elementary, or, as Neurath and Carnap called them,
“protocol,” statements their privileged position. They were no longer
thought to be incorrigible. Their truth, like that of any other physical
statements, was always open to question. But, more than this, they
lost even their judicial status. If a protocol-statement conflicted with
a statement of a higher order, such as a scientific hypothesis, one or
other of them would have to be abandoned, but it need not necessarily
be the scientific hypothesis: in certain circumstances it might be more
convenient to reject the protocol-statement instead.

As can be seen from his paper on the foundation of "knowledge
(“Uber das Fundament der Erkenntnis”) Schlick found this con-
clusion unacceptable. He argued that to treat the reports of observa-
tion, which was what protocol-statements were supposed to be, in ihis
cavalier fashion, was to put scientific hypotheses, and indeed all
would-be empirical statements, outside the control of fact. Neurath
and Carnap, however, were not impressed by this argument. They had
decided by this time that it was metaphysical to talk of comparing
statements with facts. For what could this “comparison” be if not
a logical relation? And the only thing to which a statement could
stand in any logical relation was another statement. Consequentl}^
they were led to adopt a coherence theory of truth.

Their version of the coherence theory was in some ways less
objectionable than that which the Hegelian idealists had made
familiar. Even so, for the reasons which I set out in my paper on
Verification and Experience, it seems to me quite untenable. Carnap
himself abandoned it after he had been convinced by Tarski of the
respectability of semantics; for semantics provides us with the means
of referring to the relationship between sentences and what they are
used to signify. It provides, as Tarski showed, an adequate reformu-

Editor* s Introduction [ ]

lation of the correspondence theory of truth. On the other hand
Carnap has not, so far as I know, abandoned the thesis of physicalism.
But, if he does still hold it, I think that he is mistaken. It now seems
clear to me that statements about the experiences of others can not
be logically equivalent to statements about their overt behavior; while
to maintain that the statements which one makes about one’s own
experiences are equivalent to statements about the publicly observ-
able condition of one’s body is, as Ramsey put it, to feign anaesthesia.
Nevertheless, the difficulties which this thesis was designed to meet
remain. Neither is it easy to see how else they can be avoided. I
suggest, however, that much of the trouble may arise from the ac-
ceptance of two false assumptions, the first being that for a language
to be public it must refer to public objects, and the second that in
making an empirical statement one is always referring to one’s own
experiences. I still think that empirical statements must refer to
experiences, in the sense that they must be verifiable; but the reference
need not be to the experiences of any one person, as opposed to any
other. But I acknowledge that this attempt to “neutralize” the verifi-
cation principle meets with considerable difficulties of its own.

IV. Ethics

One of the attractions, especially for Neurath, of the thesis of
physicalism was that it supported the doctrine of the Unity of Science.
In one aspect, this was less of a doctrine than a program; it was
desired that scientists of different disciplines should collaborate more
closely with each other and with philosophers than they usually do:
but it was also maintained that they were, or should be, spealdng a
common language, that the vocabulary of the sciences should be
unified. Thus, the Vienna Circle rejected the view, which many still
hold, that there is a radical distinction between the natural and the
social sciences. The scale and diversity of the phenomena with which
the social sciences dealt made them less successful in establishing
scientific laws, but this was a difficulty of practice, not of principle:
they too were concerned in the end with physical events.

Even those who did not accept the thesis of physicalism agreed
that there was no essential difference in aim or method between the
various branches of science. In the social sciences, no less than in
the natural, an attempt was made to formulate hypotheses which
could be tested by observation. Thus Schlick, who included ethics
among the social sciences, denied that its results depended upon the
use of any special faculty of moral intuition. The questions which

[ 22 ] Editors Introduction

arise in ethics are, in his opinion, questions of fact; why people hold
the principles that they do, what it is that they desire, and how their
desires can be fulfilled. In short, his general position is very similar
to that of the Utilitarians. It has much the same merits and much the
same defects.

The Vienna Circle as a whole was not very greatly interested in
ethics; but it did not dispute Schlick’s view that if ethical statements
were to be brought into the scientific fold, they must be handled in the
way that he proposed. The only question was whether they belonged
within the fold, whether they were statements of fact at aU. Carnap,
for example, maintained that they were not; he said that they were
disguised imperatives. He did not develop this suggestion, but it has
since been given substance by R. M. Hare in his book on The
Language of Morals (1952). This imperative theory of ethics may
be regarded as a version of the so-called Emotive Theorv^ which,
mainly through the work of English and American philosophers, has
come to be most closely associated with logical positivism. The
salient point is that ethical statements are not descriptive of natural
facts, still less of an alleged non-natural world of values: they are
not descriptive of anything at all. The problem is then to determine
how they do function. In C. L. Stevenson’s book Ethics a^id Lan-
guage (1944), where the emotive theor}^ was first worked out in
detail, it argued that ethical statements served the dyai purpose
of expressing their author’s approval, or disapproval, of whatever
was in question and recommending others to share his attitude. He
laid particular emphasis upon the persuasive use of ethical terms. His
views have not passed without criticism even from those who share
his general standpoint; but the alternative accounts of ethics which
these critics have put forward belong, as it were, to the same family.

In discussions of logical positivism, this theory of ethics is apt
to receive a disproportionate measure of attention, considering that it
stands on the periphery of the system. One reason for this is that it
has been thought, quite wrongly, that it was an onslaught upon
morals. It has even been asserted, without a shadow of empirical
evidence, that its advocates were corrupters of youth. In fact, the
theory only explores the consequences of a sound and respectable
point of logic which was already made by Hume; that normative
statements are not derivable from descriptive statements, or, as Hume
puts it, that “ought” does not foUow from “is.” To say that moral
judgments are not fact-stating is not to say that they are unimportant,
or even that there cannot be arguments in their favor. But these
arguments do not work in the way that logical or scientific arguments
do. It is not as if the intuitionists had discovered grounds for moral

Bditor^s Introduction [ 23 ]

judgments which the emotivists tried to take away. On the contrary,
as Mr. Strawson shows in his paper on '‘Ethical Intnitionism/" the
intnitiomsts themselves do not supply any foundation for moral
judgments. It is therefore only on personal grounds that they can be
entitled to put themselves forward as the guardians of virtue.

V. Philosophical Analysis

Some of the dissatisfaction that is aroused by the emotive theory
of ethics, and indeed by logical positivism in general, may be due to
the fact that people are still inclined to look to philosophy for guid-
ance as to the way they ought to live. When this function is denied
to it, and when it is denied even the possibility of penetrating the veil
of appearance and exploring the hidden depths of reality, they feel
that it is being trivialized. If this time-honored program is nonsensical,
what remains? As Ramsey says, “philosophy must be of some use,
and we must take it seriously.” But what function do the positivists
leave it to perform?

From the point of view of Wittgenstein’s Tractatus, its function
would appear to be purely negative, though not for that reason un-
important. “The right method of philosophy,” said Wittgenstein,
“would be this. To say nothing except what can be said, i.e. the
propositions of natural science, i.e. something that has nothing to do
with philosophy: and then always, when someone wished to say
something metaphysical, to demonstrate to him that he had given no
meaning to certain signs in his propositions. This method would be
unsatisfying to the other — he would not have the feeling that we
were teaching him philosophy — but it would be the only strictly
correct method.” This rather depressing view of the philosopher's
duty was not stiictly maintained by Wittgenstein himselL The Philo-
sophical Investigations contains a great deal more than a series of
proofs that people have failed to attach any meaning to certain signs
in their propositions. Nevertheless it still gives the impression
that to philosophize is to get into a muddle, or to rescue oneself or
others from one. Philosophy is “a battle against the bewitchment of
our intelligence by means of language.” “What is your aim in philos-
ophy? To show the &y the way out of the fly bottle.” All the same, it
is meritorious of the fly to be there. It is the critical intelligences that
get themselves bewitched.

The Tractatus left no room for philosophical propositions. The
whole field of significant discourse was covered by formal statements
on the one hand and empirical statements on the other. There re-
mained nothing for philosophy to be about. It was for this reason

[ 24 ] Editor’s Introduction

that Wittgenstein, and also Schlick, maintained that philosophy was
not a doctrine bnt an activity. The result of philosophizing, said
Schlick, would not be to accumulate a stock of philosophical propo-
sitions, but to make other propositions clear.

But to make propositions clear it must be possible to talk about
them. As Russell points out in his introduction to the Tractatus,
Wittgenstein appeared not to allow for this, or to allow for it only to
a limited extent. He implied that an attempt to describe the structure
of language, as opposed to exhibiting it in use, must result in non-
sense. But though this conclusion may have been formally accepted
by Schlick, it was in practice disregarded by the Vienna Circle. Thus,
Carnap, in his Der Logische Aufbau der Welt, explicitly set himself
to describe the structure of language by devising what he called a
‘‘Konstitution-System,’' in which the various types of linguistic ex-
pressions, or concepts, were assigned their proper places in a de-
ductive hierarchy. If he had been questioned about the status of his
own propositions, I suppose that he would have said that they were
analytic; consisting, as they did, of definitions and their logical con-
sequences, they would belong to the realm of formal truths. However
this may be, he certainly believed that these propositions were sig-
nificant; and he carried the Vienna Circle with him in holding that
they were the sort of propositions that a philosopher should be ex-
pected to put forward.

The attempt to bring philosophy within the domain of logic was
carried further by Carnap in his book on the Logical Syntax of
Language, '‘Philosophy,” he says in the forev/ord to this book, “is- to
be replaced by the logic of science — that is to say by the logical
analysis of the concepts and sentences of the sciences, for the logic
of science is nothing other than the logical syntax of the language
of science.” Though he speaks here of the language of science, he
does not hold that there need be only one. Alternative language-
systems may be devised, and the choice between them is a matier of
convenience; this is an important departure from the position of
Wittgenstein’s Tractatus. According to Carnap, a language is char-
acterized by its formation-rules, which specify what sequences of
signs are to count as proper sentences of the language, and by its
transformation-rules, which lay down the conditions under w'hich
sentences are validly derivable from one another. It might be thought
that if the language was to have any empirical application it must
also contain meaning-rules; rules which would correlate its expres-
sions with observable states of affairs: but Carnap, in this formalist
stage of his philosophy, thought that he could dispense with them.
He believed, quite mistakenly, that statements of verbal equiva-

■TEdit<fffs introduction \ [ I

Jeflces coold do the work not only of semantic statements but even
of ostensive definitions.

. . It is in this book that Carnap makes his famous distinction be-
tween the material and the formal modes of speech. He distinguishes
three kinds of sentences: “object-sentences,” such as “5 is a prime
number” or “Babylon was a big town,” “pseudo-object sentences,”
such as “Five is not a thing, but a number” “Babylon was treated of
in yesterday’s lecture,” and “syntactical sentences” such as “ ‘Five’
is not a thing-word, but a number word” “The word ‘Babylon’
occurred in yesterday’s lecture.” The pseudo-object sentences are
said to be “quasi-syntactical,” because they are syntactical sentences
masquerading as object-sentences. They are “quasi-syntacticai sen-
tences of the material mode of speech.” Translation from the material
into the foimai mode replaces them by their syntactical equivalents.
To put it less technically, when one speaks in the formal mode one
is overtly speaking about words; when one speaks in the materia!
mode one is speaking about words while seeming to speak about
things. This distinction does not of course apply to object-sentences.
Carnap was not maintaining, as some critics have supposed, that all
discourse is about words. What he did appear to overlook, liowever,
was the existence of a further category, that of pseudo-syntactical
sentences; sentences which were about things but seemed to be about
words. As a result, he was apt to fall into the error of treating these
sentences as if they were syntactical.

It is with the opposite error that he reproached most other philos-
ophers. He maintained that philosophical statements were syntactical,
but that they had been treated as if they were object-statements, be-
cause of the fashion for expressing them in the material mode of
speech. Thus, to take a selection of his examples, he argued that
"The world is the totality of facts, not of things,” the first proposition
of Wittgenstein’s Tractatiis, was equivalent to “Science is a system
of sentences, not of names”: “This circumstance is logically neces-
sary; . . . logically impossible; . . . logically possible” became
“This sentence is analytic; . . . contradictory; . . . not contradictory”:
Kronecker’s epigram “God created the natural numbers; everything
else in mathematics is the work of man” was a way of saying “The
natural-number symbols are primitive symbols; other numerical
expressions are introduced by definition.” “The only primitive data
are relations between experiences” was equivalent to “Only two-or
more-termed predicates whose arguments belong to the genus oi
experience-expressions occur as descriptive primitive symbols”: “Time
is infinite in both directions” to “Every positive or negative real-
number expression can be used as a time-co-ordinate.” Even the

r 26 1

^ Edito/s Introduction

question of determinism was said to “concern a syntactical difference
m Ae system of natural laws.” In this way rival philosophical theses
If they made any sense at all, were represented as alternative pro-
poses about die way one’s language should be formed. They were
not true or false, but only more or less convenient.

I think that Carnap’s distinction between the material and formal
modes was frmtful, in that it caUed attention to the fact that many
pMosoeucal statements are disguised statements about language.
Where he went wrong for the most part was in supposing that they
were synt^tical. For what they are concerned with is not the form
or order of words, but their use. This does not come out in Carnap’s
examples because he illicitly smuggles semantics into syntax. Thus
expenence-expressions” is not a syntactical term. What makes ari
expression an “experience-expression” is not its having any particular
form but rte being used to refer to an experience. But then the
quesbon what is to count as an experience becomes important.
Neither is it to be settled by an arbitr£iry decision.

In his more recent works, Carnap has recognized the legitimacy
ot semantics, and indeed devoted considerable attention both to the
development of semantic theory and to building up semantic sys-
tems. interesting effect of this has been a marked relaxation of
his philosophical austerity. Having acquired the right to speak of
the reference of words to things, he has allowed almost any type
or word to denote its special sort of object, thus recreating the
baroque universe which RusseU had labored to depopulate. His defense
of this apparent extravagance is to be found in his paper on “Em-
piricism Semandcs and Ontology,” where he distinguishes between
mtemal questions which arise within a given conceptual frame-
work and external” questions which concern the status and legiti-
macy of the framework itself. He himself has always been chiefly
interested in the external questions: he has thought it his business
as a philosopher to devise linguistic systems and elaborate concepts
that will be useful to the scientist. And no one should deny that this
IS a senous and legitimate activity. Where he is wrong, I think, is
m assummg that the external questions present no serious problem:
hat nothing more is at issue than a choice of linguistic forms.

It is ^s ^sregard of questions about the status of his linguistic
fram^orks that separates Carnap from the American philosophers,
like Quine and Goodman, who resemble him in their systematic
^proach to philosophy and in their preference for formal techniques.
Ihese philosophers are interested in what they call ontology, that
is, m the question how far one’s choice of language commits one to
saymg that certain things exist. “To be,” says Quine, “is to be

I

7’''' ’*■ \MUofs Introduction [ ]

j . ‘ the value of a variable”: aad this means that the extent of what
i Russell called the "‘furniture” of the world depends upon the range

I of predicates that are needed to describe it. Both Quine and Good-

man wish this furniture to be as hard and spare as possible. They
"denounce abstract entities” not just because they wish to exercise
their logical ingenuity in seeing how well they can do without them,
but because they cannot bring themselves to believe that they exist.
In the same spirit, Goodman forgoes making any use of the notion
! of possible, as opposed to actual, things, or of the distinction be-
I tween causal and accidental connections, or of that between analytic
I and synthetic statements. “You may,” he says, “decry some of these

I scruples and protest that there are more things in heaven and earth

I than are dreamt of in my philosophy. I am concerned, rather, that
there should not be more things dreamt of in my philosophy than
there are in heaven or earth.” It is not clear, however, cither in his
case or in Quine’s, on what diis demand for stringent economy is
based. Quine, indeed, allows in the end that the question of what
there is must be settled on pragmatic grounds. And so he rejoins
Carnap; but his pragmatism is much less serene.

An interest in categories, which is another way of approaching
the problem of what there is, is characteristic also of the British
philosophers who have been influenced by the later work of Witt-
genstein. But, for the most part, they are concerned not so much with
trying to eliminate certain types of entity, or to “reduce” one to
another, as with bringing out the resemblances and differences in the
functioning of the statements which ostensibly refer to them. A
technique which Wittgenstein himself uses for this purpose is that
of derising what he calls language games. The idea is that by studying
distorted or simplified models of our actual language we can obtain
a clearer insight into the way it really works. This is one w^ay of
protecting us against the error, into which we so easily fall, of as-
suming that something must be the case, instead of looking and seeing
what actually is the case. “Where our language suggests a body and
there is none, there, we should like to say, is a spirit.'' But tiiis is
to forsake description for bogus explanation. Very often the mental
processes which we are led to postulate just do not occur. For in-
stance, “it is no more essential to the understanding of a proposition
that we should imagine anything in connection with it than that
we should make a sketch from it.” Such remarks foreshadow Ryle’s
attack upon the myth of “the ghost in the machine.” And much as
Wittgenstein disliked Carnap’s methods, there is an echo of physi-
calism in his dictum that “an ‘inner process’ stands in need of out-
ward criteria.”

[ 28 ]

~ Editor’ s

has also to be taken of the influence ^ o'" E

seem to me, Iiowever that u * , Moore. It does not

cemed with ordinary usage as sudi He^h?s
upholding the “commonsefse view” of fte
the propositions which exemolifv it- hnt h !f with analyzing
we limit ourselves to orHino ^ insisted that

When he does appLl to ^ ““^y^is.

for dealing with other Dhiln<!nnh'^^ mainly as a weapon

taken htefaS thw are S ftf®' ^ words are

manifestly false It remainc ^ -ki™ muke statements which are

from w™

the discovery of their meani/o- n appear to be saying, but then
using words in any ordinarv sfn£- ^ problern. K they are not

them has to be made cl^ ’ *®y rising

schTO?” hLS acWevement of the “ordinary-language

tific” uses of language. t^issection of the “unscien-

description of what he calls nerfru^^?^^ ^ -Austin’s

“I know . . .» or “I pJJ^se statements like

assert a fact but to ccLmit the ’<:rv. purpose is not to

some sort of guarantee To wha^ ° ^^y^

flexibility in the approach to Hna ™^§^^hve lengths this greater
WaismaL’s pSer S by Dr.

current conception of nhiincn v ^t shows that the

Ramsey’s ide^ of philmoSiv^f ^Pmad far beyond

Ramsey was right in savimr toac .®™P.y m definitions. But

clarifying

VI.

devetopS“?tojc“£:SL'’r “=•““='

main points of coS^SS ^ , and the

over many pieces that I sLu have wSf 1“ T’

CoweSton,’’°in^wWch^toe°oo’^ 5

is effectively criticized or for Cani?’ pf 'i Priori statements

bilify and Me^n^ IfTq 1/ f ^ ® ^uential articles on “Testa-
contoins nothing of Witt^ens^l^^I T be regretted that the volume
PA/toxopW ni the^JS T: r’'

sodic charter Ts a wS to S’ H for all their epi-

passages. They have to be read a^fwSe!'^

Logical Atomism

BY BERTRAND RUSSELL

The philosophy which I advocate is generally regarded as a species
of realism, and accused of inconsistency because of the elements
in it which seem contrary to that doctrine. For my part, I do not
regard the issue between realists and their opponents as a funda-
mental one; I could alter my view on this issue witiiout changing
my mind as to any of the doctrines upon which I wish to lay stress.
I hold that logic is what is fundamental in philosophy, and that
schools should be characterized rather by their logic than by their
metaphysic. My own logic is atomic, and it is this aspect upon
which I should wish to lay stress. Therefore I prefer to describe
my philosophy as “logical atomism,” rather than as “realism,”
whether with or without some prefixed adjective.

A few words as to historical development may be useful by way
of preface. I came to philosophy through mathematics, or rather
through the wish to find some reason to believe in the truth of
mathematics. From early youth, I had an ardent desire to believe
that there can be such a thing as knowledge, combined with a great
dfficulty in accepting much that passes as knowledge. It seemed
clear that the best chance of finding indubitable truth would be in
pure mathematics, yet some of Euclid’s axioms were obviously doubt-
ful, and the infinitesimal calculus, as I was taught it, was a mass
of sophisms, which I could not bring myself to regard as anything
else. I saw no reason to doubt the truth of arithmetic, but I did not
then know that arithmetic can be made to embrace all traditional
pure mathematics. At the age of eighteen I read Mill’s Logic, but
was profoundly dissatisfied with his reasons for accepting arithmetic
and geometiy. I had not read Hume, but it seemed to me that pure
empiricism (which I was disposed to accept) must lead to scep-

This essay was RusselFs contribution to Contsmporary British Philosophy, first
series (ed. J. H, Muirhead), a book published in 1924. It is here reprinted by the
kind pennission of the author and George Alien and Unwin Ltd., London.

■fm-

j

[ 31 ]

[ 32 ] BERTRAND RUSSELL

ticism rather than to Mill’s support of received scientific doctrines.
At Cambridge I read Kant and Hegel, as well as Mr. Bradley’s
Logic, which influenced me profoundly. For some years I was a
disciple of Mr. Bradley, but about 1898 I changed my views, largely
as a result of arguments with G. E. Moore. I could no longer believe
that knowing makes any difference to what is known. Also I found
myself driven to pluralism. Analysis of mathematical propositions
persuaded me that they could not be explained as even partial
truths unless one admitted pluralism and the reality of relations.
An accident led me at this time to study Leibniz, and I came to the
conclusion (subsequently confirmed by Couturat’s masterly re-
searches) that many of his most characteristic opinions were due
to the purely logical doctrine that every proposition has a subject
and a predicate. This doctrine is one which Leibniz shares with
Spinoza, Hegel, and Mr. Bradley; it seemed to me that, if it is
rejected, the whole foundation for the metaphysics of all these
philosophers is shattered. I therefore returned to the problem which
had originally led me to philosophy, namely, the foundations of
mathematics, applying to it a new logic derived largely from Peano
and Frege, which proved (at least, so I believe) far more fruitful
than that of traditional philosophy.

In the first place, I found that many of the stock philosophical
arguments about mathematics (derived in the main from Kant)’
had been rendered invalid by the progress of mathematics in the
meanwhile. Non-Euclidean geometry had undermined the argument
of the transcendental aesthetic. Weierstrass had shown that the
differential and integral calculus do not require the conception of
the infinitesimal, and that, therefore, all that had been said by
philosophers on such subjects as the continuity of space and lime
and motion must be regarded as sheer error. Cantor freed the
conception of infinite number from contradiction, and thus disposed
of Kant’s antinomies as well as many of Hegel’s. Finally Frege
showed in detail how arithmetic can ho deduced from pure logic,
without the need of any fresh ideas or axioms, thus disproving Kanf s
assertion that “7 4-5 = 12” is synthetic — at least in the obvious
interpretation of that dictum. As all these results were obtained, not
by any heroic method, but by patient detailed reasoning, I began
to think it probable that philosophy had erred in adopting heroic
remedies for intellectual difficulties, and that solutions were to be
found merely by greater care and accuracy. This view I have come
to hold more and more strongly as time went on, and it has led me
to doubt whether philosophy, as a study distinct from science and

Atomism [ 33 ]

‘ pxsesseh of a method of its own, is anything more than an nn-
^omte legacy from theology.

Fiege’s work was not JBnal, in the first place because it applied
only to arithmetic, not to other branches of mathematics; in the
second place because his premises did not exclude certain contra-
dictions to which ail past systems of formal logic turned out to be
liable. Dr. Whitehead and I in collaboration tried to remedy these
two defects,! in Frincipia Mathematical which, however, still falls
short of finality in some fundamental points (notably the axiom
of reducibilit>0 • spite of its shortcomings I think that no

one who reads this book will dispute its main contention, namely,

I that from certain ideas and axioms of formal logic, by the help of
the logic of relations, all pure mathematics can be deduced, with-
out any new undefined idea or unproved propositions. The technical
methods of mathematical logic, as developed in this book, seem to
me very powerful, and capable of providing a new instrument for
the discussion of many problems that have hitherto remained sub-
ject to philosophic vagueness. Dr. Whitehead's Concept of Nature
and Principles of Natural Knowledge may serv'e as an illustration
of what I mean.

When pure mathematics is organized as a deductive system —
i.e. as the set of all those propositions that can be deduced from
an assigned set of premises — it becomes obvious that, if we are
to believe in the truth of pure mathematic.s. it cannot be solely because
we believe in the truth of the set of premises. Some of the premises
are much less obvious than some of their consequences, and are
believed chiefly because of their consequences. This will be found
to be always the case when a science is arranged as a deductive
system. It is not the logically simplest propositions of the system
that are the most obvious, or that provide the chief part of our
reasons for believing in the system. With the empirical sciences this
is evident. Electro-dynamics, for example, can be concentrated into
Maxwell’s equations, but these equations are believed because of
the observed truth of certain of their logical consequences. Exactly
the same thing happens in the pure realm of logic; the logically
first principles of logic — at least some of them — are to be believed,
not on their own account, but on account of their consequences.
The epistemological question: “Why should I believe this set of
propositions?” is quite different from the logical question: “What
is the smallest and logically simplest group of propositions from
which this set of propositions can be deduced?” Our reasons for
believing logic and pure mathematics are, in part, only inductive and

[ 34 ]

. BERTRAND RUSSELL

StSJof ? f order, the propo-

irf hir ^ ™P°rtaBt, sirens

ordor ^ i assimilating the logical to the epistemolo<ncaI

w Iram assimilating a, apisteSSS

(hSro^t J® falsehood of mathematics is by

STSa^VnTr'h ““\™» “I-ows aat maaamatics

that mathematics is true would require
otner methods and other considerations. ^

T f important heuristic maxim which Dr. Whitehead and

I found, by exi^ijnce, to be applicable in mathemafe^lS Sd
have sm^ applied in various other fields, is a form of Sam’s
t£°k supposed entities has neat logical proper-

Im be r^nlao^H 'h ^ instances, that the supposed Ltities

whirh K ^ ^ purely logical structures composed of entities

« have not sneh neat properties. In that case, in interpretog a
body of propositions hitherto believed to be about the Lnnosed

in^i» detail of the body of propositions in question. This is

infern°Tnd properties are always

f rred, and if the propositions in which they occur cab be inter-

doubtful stTo ThJ P™P°^dions is secured against the need of a
aoubdul step. The pnnciple may be stated in the form: “Wherever

possible, substitute constructions out of known entities for inferences
to unknown entities.” fmcicnccs

.. diis principle are very various, but are not intelli-

gib e m detail to those who do not know mathematical logic. The
first iiKtance I came across was what I have called “the principle
^abstraction, or “the principle which dispenses with abstraction^”!
SLiivT*"' w- '' ‘^ase of any symmetrical and

StTnm / r’ “ ^P‘ to i”for that such

otheTBu? S “ some'cases'^and uo“S

^'iT ^ all the formal purposes of a common quality can be
rved by membership of the group of terms having the said rela-
tion to a given term. Take magnitude, for example. Let us suppose

Sa ^ is easy to su^ose

sW But ll n r quality caUed their length, which th?y all
Share. But all propositions m which this supposed quality occurs will

1. Our Knowledge of the External World, p. 42.

Atomisfk [ 35 ]

'' rciaiii their toith-valiie unchanged if, instead of ‘length of the rod x”
wi take “membership of the group of all those rods which are as
long as In various special cases — e.g. the definition of real num-
bers — ^a simpler construction is possible*

A very important example of the principle is Frege’s definition
of the cardinal number of a given set of terms as the class of all
sets that are “similar” to the given set — where two sets are “similar”
wlien there is a one-one relation whose domain is the one set and
wliose converse domain is the other. Thus a cardinal number is
the class of all those classes which are similar to a given class. This
definition leaves unchanged the truth-values of all propositions in
which cardinal numbers occur, and avoids the inference to a set of
entities called “cardinal numbers,” which were never needed except
for the purpose of making arithmetic intelligible, and are now no
longer needed for that purpose.

i Perhaps even more important is the fact that classes themselves
can be dispensed with by similar methods. Mathematics is full of
propositions which seem to require that a class or an aggregate
should be in some sense a single entity — e.g. the proposition “the
number of combinations of n things any number at a time is 2”.”
Since 2^ is always greater than n, this proposition leads to difficulties
if classes are admitted because the number of classes of entities in
the universe is greater than the number of entities in the universe,
which would be odd if classes were some among entities. Fortunately
all the propositions in which classes appear to be mentioned can
be interpreted without supposing that there are classes. This is
perhaps the most important of all the applications of our principle.
(See Frincipia Mathematica, *20.)

Another important example concerns what I call “definite
descriptions,” i.e. such phrases as “the even prime,” “the present
King of England,” “the present King of France.” There has always
been a difficulty in interpreting such propositions as “the present
King of France does not exist.” The difficulty arose through suppos-
ing that “the present King of France” is the subject of this proposi-
tion, which made it necessary to suppose that he subsists although he
does not exist. But it is difficult to attribute even subsistence to “the
round square” or “the even prime greater than 2.” In fact, “the
round square does not subsist” is just as true as “the present King
of France does not exist.” Thus the distinction between existence
and subsistence does not help us. The fact is that, when the words
“the so-and-so” occur in a proposition, there is no corresponding
single constituent of the proposition, and when the proposition is

I Jt)J

,,, , j , BERTRAND RUSSELL

so-and-so to sT^ “r J so-and-so exists, and x is the

which it is ascribed nonsense Existence, in the sense in

frS^ the hst of altogether

S Tts refutations ontological argument and most

Principia Mathematica, * 14 ) grammar. (See

tionJforinfr^p™^^- examples of the substitution of construc-

physics. examples la

f sS£S

time pervaded all aU time, and an instant of

wants^as nehhS SSal mathematical physics

are constructed bv E thr extension.) Event-particles

and insS?s were Points

UeiTTherefo”" *="o»n ”4?nS“’if'tt'S''

be constructed If tL wnfident that event-particles can

as to meet those nf troJrf requirements

two pieces of matter cannot he at tt. TOnstniction; first, that

re”Se,'‘£

ettces mates one snspicions of^SS“^rcr!S.t,';

.’■■r ' ' , , I

^ ' I

togicai Atomism | [ 37 ]

bannot help feeling that impenetrability is not an empirical fact,
derived from observation of billiard-balls, but is something logically
necessary. This feeling is wholly justified, but it could not be so
if matter were not a logical construction. An immense number of
occurrences coexist in any little region of space-time; when we are
speaking of what is not logical construction, we find no such prop-
erty as impenetrability, but, on the contrary, endless overlapping
of the events in a part of space-time, however small. The reason
that matter is impenetrable is because our definitions make it so.
Speaking roughly, and merely so as to give a notion of how this
happens, we may say that a piece of matter is all that happens in
a certain track in space-time, and that we construct the tracks called
bits of matter in such a way that they do not intersect. Matter
is impenetrable because it is easier to state the laws of physics if
we make our constructions so as to secure impenetrability. Impene-
trability is a logically necessary^ result of definition, though the fact
that such a definition is convenient is empirical. Bits of matter are
not among the bricks out of which the world is built. The bricks
are events, and bits of matter are portions of the structure to which
we find it convenient to give separate attention.

In the philosophy of mental occurrences there are also oppor-
tunities for the application of our principle of constructions versus
inferences. The subject, and the relation of a cognition to what is
known, both have that schematic quality that arouses our suspicions.
It is clear that the subject, if it is to be preserved at all, must be
preserved as a construction, not as an inferred entity; the only question
is whether the subject is sufficiently useful to be worth constructing.
The relation of a cognition to what is known, again, cannot be a
straightforward single ultimate, as I at one time believed it to be.
Although I do not agree with pragmatism, I think William James
was right in drawing attention to the complexity of “knowing.” It
is impossible in a general summary, such as the present, to set out
the reasons for this view. But whoever has acquiesced in our prin-
ciple wiU agree that here is prima facie a case for applying it.
Most of my Analysis of Mind consists of applications of this prin-
ciple. But as psychology is scientifically much less perfected than
physics, the opportunities for applying the principle are not so good.
The principle depends, for its use, upon the existence of some fairly
reliable body of propositions, which are to be interpreted by the
logician in such a way as to preserve their truth while minimizing
the element of inference to unobserved entities. The principle there-
fore presupposes a moderately advanced science, in the absence

1 J

f I,. , , BERTRAND RUSSELL

lTa»°Lr “« l» P-rely pmvisionl “

1 liave been speaking hitherto of what it is not neri^<^^ur^r t

corr^Z",? ““r" of tha wZd S l^eS

are w'te ^'° ^ ^“estioii, as to what these mateiiak

to repLett ^ “ ''!■« <l^y tiy

influence of language on philosophy has, I believe been

i T„~rh=' “ •“

ask ourselves detoSy how tar U " Sttaare Th“’ “u*? “
brought

be used tia^ifican% TtanS for^?^ ^ nameAvhich can

there is a certnfn L . ^ suppose that

because tVie persistent being called “Socrates ”

we are led to're^vard^'^ applied to a series of occurrences which
gro4 “re aSfr S , ‘“"S' As language

nare^ .h„e repres;ntd“; “1!!^

there ™ Inv’Tr uuiversals b:, c rtainly

" "ria„Shri« ri''"';- ““r"" “bi-

mieleads uj boik^y "J “caSw Sd k T '“P““

be on our suard in hntfi syntax. We must

false rnktaph^"" '“P^ ■« «« 'ogle is not to lead to a

s«l“£s:~rS" — ■

hVS':he%t'.o“S”r' wZ'kt-”

sense is influenced by flte existent TtewMd^Tid’toiTS,^

Atomism ^ [ 39 ]

■ pose that one word must stand for one object, which will be a
uiiiversai in the case of an adjective or an abstract word. Thus the
lufluence of vocabulary is towards a kind of platonic pluralism of
things and ideas.

The influence of syntax, in the case of the Indo-European lan-
guages, is quite different. Almost any proposition can be put into
a form in which it has a subject and a predicate, united by a copula.
It is natural to infer that every fact has a corresponding form, and
consists in the possession of a quality by a substance. This leads,
of course, to monism, since the fact that there were several sub-
stances (if it were a fact) would not have the requisite form.
Philosophers, as a rule, believe themselves free from this sort of
influence of linguistic forms, but most of them seem to me to be
mistaken in this belief. In thinking about abstract matters, the
fact that the words for abstractions are no more abstract than ordin-
ary words always makes it easier to think about the words than
about what they stand for, and it is almost impossible to resist
consistently the temptation to think about the words.

Those who do not succumb to the subject-predicate logic are
apt to get only one step further, and admit relations of two terms,
such as before-^md-after, greater-and-less, right-and-left. Language
lends itself to this extension of the subject-predicate logic, since
we say precedes U/' exceeds B/' and so on. It is easy to
prove that the fact expressed by a proposition of this sort cannot
consist of the possession of a quality by a substance, or of the
possession of two or more qualities by two or more substances.
(See Principles of Mathematics, § 214.) The extension of the sub-
ject-predicate logic is therefore right so far as it goes, but obviously
a further extension can be proved necessary^ by exactly similar
arguments. How far it is necessary' to go up the series of three-
term, four-term, five-term . . . relations I do not know. But it is
certainly necessary to go beyond two-term relations. In projective
geometry, for example, the order of points on a line or of planes
through a line requires a four-term relation.

A very unfortunate effect of the peculiarities of language is in
connection with adjectives and relations. All words are of the same
logical type; a word is a class of series, of noises or shapes according
as it is heard or read. But the meanings of words are of various
different types; an attribute (expressed by an adjective) is of a
different type from the objects to which it can be (whether truly
or falsely) attributed; a relation (expressed perhaps by a preposi-
tion, perhaps by a transitive verb, perhaps in some other way) is

[40]

BERTRAND RUSSELL

TOt\oM^Th! v°“ between which it holds or does

of tit f’ ^^^bon of a logical type is as follows: A and B are
the same logical type if, and only if, given any fact of which A

iorntimenf h ^ corresponding fact which has 5 as a

*d ArlsS illustration, Socrates

® s^ibe type, because “Socrates was a philos-

Sd Cal,^!l ^ philosopher” are both facts; S^l:rates

ODhe?^S “rT 1 “Socrates was a philos-

t I af Cahgula was not a philosopher” are both facts. To love

“Pl.,to *yPC’ because “Plato loved Socrates” and

fmm tht^ Socrates” are both facts. It follows formally

trom the defimtion that, when two words have meanings of differ-

dHT-^Sm ^hey mean are of
iTurent tjpes, that is to say, there is not one relation of meanincr

between words and what they stand for, but as many relations of
of a different logical type, as there are logical types
amon^ the objects for which there are words. Tliis fact is a very
potent source of error and confusion in philosophy. In particular,
t has made it extraordinarily difficult to express in words any
theory' of relations which is logically capable of being true, because
language cannot preserye the difference of type between a relation
and Its terms. Most of the arguments for and against the reality of
relations have_ been yitiated through this source^ of confusion.

At this point. 1 propo.se to digress for a moment, and to say. as
shortly- as I can, what I belieye about relations. My own yiews on
the subject of relations in the past were less clear than I thought
hem. but were by no means the yiews which my critics supposed
them to be. Owing to lack of clearness in my own thoughts, I was
unable to conyey my meaning. The subject of relations 'is difficult,
and i am far from claiming to be now dear about it. But .1 think
certain points arc clear to me. At the time when I wrote The
Principles o; Mathematics, I had not yet seen the necessity of lo.gical
types. The doctrine of types profoundly affects logic, and I think
shows what, exactly, is the yalid element in the arguments of those
who oppose “external” relations. But so far from strengthening
their mam position, the doctrine of types leads, on the contrary,
to a more complete and radical atomism than any that I conceived
to possible twenty years ago. The question of relations is one
of the most important that arise in philosophy, as most other issues
turn on it: momsm and pluralism; the question whether anything
IS wholly trae except the whole of truth, or wholly real except the

Logical Atomism [ ]

wliole of reality; idealism and realism, in some of their forms;
perhaps the very existence of philosophy as a subject distinct from
science and possessing a method of its own. It will serve to make
my meaning clear if I take a passage in Mr. Bradley’s Essays on
Truth and Reality, not for controversial purposes, but because it
raises exactly the issues that ought to be raised. But first of all I
will try to state my own view, without argument.^

Certain contradictions — of which the simplest and oldest is the
one about Epimenides the Cretan, who said that all Cretans were
liars, which may be reduced to the man who says “I am lying” —
convinced me, after five years devoted mainly to this one question,
that no solution is technically possible without the doctrine of types.
In its technical form, this doctrine states merely that a word or
symbol may form part of a significant proposition, and in this
sense have meaning, without being always able to be substituted
for another word or symbol in the same or some other proposition
without producing nonsense. Stated in this way, the doctrine may
seem like a truism. “Brutus killed Caesar” is significant, but “Killed
killed Caesar” is nonsense, so that we cannot replace “Brutus” by
“killed,” although both words have meaning. This is plain common
sense, but unfortunately almost all philosophy consists in an
attempt to forget it. The follow'ing words, for example, by their
very nature, sin against it: attribute, reiaiion, complex, fact, truth,
falsehood, not, liar, omniscience. To give a meaning to these wx)rds,
we have to make a detour by way of words or symbols and the
different ways in which they may mean; and even then, we usually
arrive, not at one meaning, but at an infinite series of different
meanings. Words, as we saw, are all of the same logical type; there-
fore when the meanings of two words are of different types, the
relations of the two words to what they stand for are also of different
types. Attribute-words and relation-words are of the same type,
therefore we can say significantly “attribute-words and relation-
words have different uses.” But we cannot say significantly “attributes
are not relations.” By our definition of types, since relations are
relations, the form of words “attributes are relations” must be not
false, but meaningless, and the form of w^ords “attributes are not
relations,” similarly, must be not true, but meaningless. Nevertheless,
the statement “attribute-words are not relation-words” is significant
and true.

2. I am much indebted to my friend Wittgenstein in this matter. See his Trac-
iatus Logico-Philosophicus, BCegan Paul, 1922. I do not accept all his doctrines,
but my debt to him will be obvious to those who read his book.

[ 42 ]

BERTRAND RUSSELL

tJr>r,c question of internal and external rein

are S"^1.T “S

'° 'iMrine of external relatioiis It is 2de^ to

say terns are independent of their relations ” bec?ui “Si

tetu” Inv toZ" r “ TWO events^ar^ s “dt

Se oS thTs to one to

die sepaition beK tte ewniTk spSto OMoS th °
ae^se of "fadepeadem” is relevant. If, sav"?^ ^

two sSnSnst 1. H ^ third term between the other

the utmost ^care. ^ "^lust be avoided with

PriiSfv °f external relations'?

equTvaTeL foil's f°° P'-oPO^ition is not, in general, logically
sited morirJi- SvS ^^^i^fP^dicate propositions"

2’^ 5 “ general the case that we can findoredicateci S

f^here'r of x and j', xi?y is equivalent to xc, y(i (x y)y

me or consisting of x and v)! or to any

one or mo of these. This, and this only, is what I mean to nffirJ

ipart oihal relations; and this, clearly', ^ at

iutei riai torine of

In place of “unities” or “complexes,” I prefer to sneak of “fqptc ”
?andv1n^ Understood that the word “fact” cannofoccur signifi-
^ position m a sentence where the word “simnle” can

^ur si^cantly, nor can a fact occur where a simple c^ occT
We must not say “facts are not simples ” We can cav “Thf. c k i
for a fact must not replace the sSl fo7:

^ ^ P^®s®rved.” But it should be observed that’

in this sentence, the word “for” has different meanings on the^o
occasions of its use. If we are to have a language wiSh is to sS-

Atomism [ 43 ]

guard us from errors as to types, the symbol for a fact must be a
proposition, not a single word or letter. Facts can be asserted or
denied, but cannot be named. (When I say “facts cannot be named/"
this is, strictly speaking, nonsense. What can be said without falling
into nonsense is: “The symbol for a fact is not a name.”) This
illustrates how meaning is a different relation for different types.
The way to mean a fact is to assert it; the way to mean a simple is
to name it. Obviously naming is different from asserting, and
similar differences exist where more advanced types are concerned,
though language has no means of expressing the differences.

There are many other matters in Mr. Bradley’s examination of
my views which call for reply. But as my present purpose is explan-
atoiy rather than controversial, I will pass them by, having, I hope,
already said enough on the question of relations and complexes
to make it clear what is the theory that I advocate. I will only add,
as regards the doctrine of types, that most philosophers assume
it now and then, and few would deny it, but that all (so far as I
know) avoid formulating it precisely or drawing from it those
deductions that are inconvenient for their systems.

I come now to some of Mr. Bradley’s criticisms (Joe. cit,,
p. 280 ff.). He says:

“Mr. Russell’s main position has remained to myself incomprehen-
sible. On the one side I am led to think that he defends a strict pluralism,
for which nothing is admissible beyond simple terms and external rela-
tions. On the other side Mr. Russell seems to assert emphatically, and
to use throughout, ideas which such a pluralism surely must repudiate.
He throughout stands upon unities which arc complex and which cannot
be analysed into terms and relations. These two positions to my mind
are irreconcilable, since the second, as I understand it, contradicts the
first flatly.”

With regard to external relations, my view is the one I have just
stated, not the one commonly imputed by those who disagree. But
with regard to unities, the question is more difficult. The topic is
one with which language, by its very nature, is peculiarly unfitted
to deal. I must beg the reader, therefore, to be indulgent if what I
say is not exactly what I mean, and to try to see what I mean in
spite of unavoidable linguistic obstacles to clear expression.

To begin with, I do not believe that there are complexes or
unities in the same sense in which there are simples. I did believe
this when I wrote The Principles of Mathematics, but, on account
of the doctrine of types, I have since abandoned this view. To

[44 1

■* BERTRAND RUSSELL

speak loosdy, I regard simples and complexes as always of differ-
ent types. That is to say, the statements “There are simples” and
There are complexes” use the words “there are” in different senses
But if I use the words “there are” in the sense which they have in
the statement there are simples,” then the form of words “there
are not complexes” is neither true nor false, but meaningless. This
shows how difficult It is to say clearly, in ordinary language, what
ir, Jr say about complexes. In the language of mathematical
logic It IS much easier to say what I want to say, but much harder
to induce people to understand what I mean when I say it

When I speak of “simples” I ought to explain that I am speaking
of somethmg not experienced as such, but known only inferentially
as he limit of analysis. It is quite possible that, by greater logical
skill, the need for assuming them could be avoided. A logical lan-
page will not lead to error if its simple symbols (i.e. those not
aving any parts that are symbols, or any significant structure) all
sand fc^ objects of some one type, even if these objects are not
simple The only drawback to such a language is that it is incapable
of dealing with anything simpler than the objects which it repre-
sente by simple symbols. But I confess it seems obvious to me (as
1 did to Leibniz) that what is complex must be composed of
smples, though the number of constituents may be^ infinite. It is
also obvious that the logical uses of the old notion of substance
ae. those uses which do not imply temporal duration) can only
tw applied, if at all, to simples; objects of other types do not have
mat land of being which one associates with substances. The
essence of a substance, from the symbolic point of view, is that it
can only be named — in old-fashioned lanauaae, it never occurs in a
proposition except as the subject or as one of the terms of a rela-
tion. If what we take to be simple is really complex, we may get
into trouble by naming it, when what we ought to do is to assert
It For example, if Plato loves Socrates, there is not an entity
Plato s loye for Socrates.” but only the fact that Plato loves
Socrates. And in speaking of this as “a fact,” we are already making
It more substantial and more of a unity than we have any right to do
Attributes Md relations, though they may be not susceptible
of analysis, differ from substances by the fact that they suggest a
structure, and that_ there can be no significant symbol which
symbolizes them in isolation. AH propositions in which an attribute
or a relation seems to be the subject are only significant if they can
be brought into a form in which the attribute is attributed or the
relation relates. If this were not the case, there would be significant

Atomism [ 45 ]

' pioiK)sitiom in wMch an attribute or a relation would occupy a
position appropriate to a substance, which would be contrary to
i the doctrine of types, and would produce contradictions. Thus
the proper symbol for “yellow” (assuming for the sake of illustration
that this is an attribute) is not the single word “yellow,” but the
propositional function “x is yellow,” where the structure of the
symbol shows the position which the word “yellow” must have if
it is to be significant. Similarly the relation “precedes” must not be
represented by this one word, but by the symbol '"x precedes y,”
showing the way in which the symbol can occur significantly. (It
is here assumed that values are not assigned to x and y when we
are speaking of the attribute or relation itself.)

The symbol for the simplest possible kind of fact will still be of
the form ''x is yellow” or “x precedes y/' only that “x” and will be
no longer undetermined variables, but names.

In addition to the fact that we do not experience simples as such,
there is another obstacle to the actual creation of a correct logical
language such as I have been trying to describe. This obstacle is
vagueness. All our words are more or less infected with vagueness,
by which I mean that it is not always clear whether they apply to
a given object or not. It is of the nature of words to be more or less
general, and not to apply only to a single particular, but that
would not malce them vague if the particulars to which they applied
were a definite set. But this is never the case in practice. The defect,
however, is one which it is easy to imagine removed, however
dfficult it may be to remove it in fact.

The purpose of the foregoing discussion of an ideal logical lan-
guage (which would of course be whoHy useless for daily life) is
twofold: first, to prevent inferences from the nature of language
to the nature of the world, which are fallacious because they
depend upon the logical defects of language; secondly, to suggest,
by inquiring what logic requires of a language which is to avoid
contradiction, what sort of a structure we may reasonably suppose
the world to have. If I am right, there is nothing in logic that can
help us to decide between monism and pluralism, or between the
view that there are ultimate relational facts and the view that there
are none. My own decision in favor of pluralism and relations is
taken on empirical grounds, after convincing myself that the a
priori arguments to the contrary are invalid. But I do not think
these arguments can be adequately refuted without a thorough
treatment of logical types, of which the above is a mere sketch.

This brings me, however, to a question of method which I

believe to be very important What a + tjund russell

ophy? What shS hf? i« PMos-

bein^ tn>t> ,u . ® ^ the greatest likelihood of

ii other evidence? Tt ^ prop®^ to be rejected if it conflicts with
likelihood of betog trSrin

advanced rr Hn “the mam than any philosophy hitherto

I L “y them

there 2 nZe “ PMosophy

mafb^ ^ proposition in a scieni

a^fat St ’ ?i n there are some thS

because tife rick nf^ ^ um philosophy upon science,

at , . error m philosophy is pretty sure to be ereater

X^^oXb. «r ““’“.‘■“P' ‘o' X? in pMos^rS

coumL^hZ^ those philosophers whose theories, prirmi facie, run
thaT t chal be able to interpret science so

S rith 1- °wn level, with that minor degree

of truth which ought to content the humble scientist. Those who

how In defa^rr 1^" ^t seems to me-to

show m detail how the mterpretation is to be effected In manv

for'1mtaScS''ASlh^'' would be quite impossible. I do not believe",
or instance, that those who disbelieve in the reality of relations

Even if r^M '”P'“y asymmetricai iriations.
tyen If I could see no way of answering the objections to relations

hkdv th?n St”!w^ ^ still think it more

likely than not that some answer was possible, because I should

think an error in a very subtle and abstract argument more probable

thimr we f falsehood in science. Admittine that everv-

thmg we beheve ourselves to kmow is doubtful, it seems, nevertheless

Si thlnlhl det n “ philosophy is more doubt-

itc Snci* ^ though perhaps not more doubtful than

Its most sweeping generalizations.

nkti question of interpretation is of importance for almost every
feSidtc and I am not at all inclined to deny that manv scientifc
results require interpretation before they can be fitted into a co-
herent philosophy. The maxim of “constructions ver.ur Serences^

IS itseff a m^im of interpretation. But I think that any valid kind
of mterpretation ought to leave the detaff unchangeth though
ay give a new meanmg to fundamental ideas. In practice this
meMs that structure must be preserved. And a test of this is that
all the propositions of a science should remain, though new mean-

[ 47 ]

be found for their terms, A case in point, on a non-
level, is the relation of the physicd theory of light
our perceptions of color. This provides different physical occur-
rences corresponding to different seen colors, and thus makes the
structure of the physical spectrum the same as that of what we see
when we look at a rainbow. Unless structure is preserved, we cannot
validly speak of an interpretation. And structure is just what is
destroyed by a monistic logic.

I do not mean, of course, to suggest that, in any region of science,
structure revealed at present by observation is exactly that
actually exists. On the contrary, it is in the highest degree
that the actual structure is more fine-grained than the
observed structure. This applies just as much to psychological as
to physical material. It rests upon the fact that, where we perceive
a difference (e.g. between two shades of color), there is a differ-
ence, but where we do not perceive a difference it does not follow
that there is not a difference. We have therefore a right, in all inter-
pretation, to demand the preservation of observed differences, and
the provision of room for hitherto unobserved differences, although
we cannot say in advance what they will be, except when they can
be inferentially connected with observed differences.

In science, structure is the main study. A large part of the im-
portance of relativity comes from the fact that it has substituted a
single four-dimensional manifold (space-time) for the two mani-
folds, three-dimensional space and one-dimensional time. This is a
change of structure, and therefore has far-reaching consequences,
but any change which does not involve a change of structure does
not make much difference. The mathematical definition and study
of structure (under the name of ‘Velation-numbers”) form Part IV
of Principia Mathematical

The business of philosophy, as I conceive it, is essentially that
of logical analysis, followed by logical synthesis. Philosophy is more
concerned than any special science with relations of different sciences
and possible conflicts between them; in particular, it cannot acquiesce
in a conflict between physics and psychology, or between psychology
and logic. Philosophy should be comprehensive, and should be bold
in suggesting hypotheses as to the universe which science is not
yet in a position to confirm or confute. But these should always
be presented as hypotheses, not (as is too often done) as immutable
certainties like the dogmas of religion. Although, moreover, com-
prehensive construction is part of the business of philosophy, I do
not believe it is the most important part. The most important part,

r 48 1

-* BERTRAND RUSSELL

to my I^d, consists in criticizing and clarifying notions which are
apt to be regarded as fundamental and accepted uncritically. As
instances I might mention: mind, matter, consciousness, knowledge
experience, causality, will, time. I believe all these notions to be
inexact and approximate, essentially infected with vagueness in-
capable of forming part of any exact science. Out of the oririnal
manifold of events, logical structures can be budt which will have
properties sufficiently like those of the above common notions to
account for their prevalence, but sufficiently unlike to allow a great
deal of error to creep in through their acceptance as fundamental.

the following as an outline of a possible structure of
the world; it is no more than an outline, and is not offered as more
than possible.

'ae world consists of a number, perhaps finite, perhaps infinite,
ot entities which have various relations to each other, and perhaps
also vanous quafities. Each of these entities may be called an
event , from the point of view of old-fashioned physics, an event
occupies a short finite time and a small finite amount of space, but
as we are not going to have an old-fashioned space and an old-
rashioned time, this statement cannot be taken at its face value.
Eveiy event has to a certain number of others a relation which may
be called compresence”; from the point of view of physics, a col-
lection of compresent events all occupy one small region in space-
time. One example of a set of compresent events is what would
be called the contents of one man’s mind at one time — i.e. all his
sensations, images, memories, thoughts, etc., which can coexist
temporally. His visual field has, in one sense, spatial extension, but
this must not be confused with the extension of physical space-time;
every part of his visual field is compresent with every' other part
and with the rest of “the contents of his mind” at that time, ‘and
a collection of compresent events occupies a minimal region in
pace-time. There are such collections not only where there are
brains, but everywhere. At any point in “empty space,” a number
OT stars could be photographed if a camera were introduced- we
believe thOT light travels over the regions intermediate between its
source and our eyes, and therefore something is happening in these
regions. If fight from a number of different sources reaches" a certain
minimal region in space-time, then at least one event corresponding
o each of these sources exists in this minimal region, and all these
events are compresent.

«r compresent events as a “minimal region.”

e find that mmimal regions form a four-dimensional maffifold,

Atomism

that,'. by a little logical manipulation, we can construct from
* ' ^tm the manifold of space-time that physics requires. We find also
. / that, from a number of different minimal regions, we can often
^ ' pick out a set of events, one from each, which are closely similar
when they come from neighboring regions, and vary from one region
" to another according to discoverable laws. These are the laws of the
propagation of light, sound, etc. We find also that certain regions
in space-time have quite peculiar properties; these are the regions
which are said to be occupied by "‘matter.” Such regions can be
collected, by means of the laws of physics, into tracks or tubes, very
much more extended in one dimension of space-time than in the
other three. Such a tube constitutes the “history” of a piece of
matter; from the point of view of the piece of matter itself, the
dimension in which it is most extended can be called “time,” but
it is only the private time of that piece of matter, because it does
not correspond exactly with the dimension in which another piece of
matter is most extended. Not only is space-time very peculiar within
a piece of matter, but it is also rather peculiar in its neighborhood,
growing less so as the spatio-temporal distance grows greater; the
law of this peculiarity is the law of gravitation.

All kinds of matter to some extent, but some kinds of matter
(viz. nervous tissue) more particularly, are liable to form “habits,”
i.e. to alter their structure in a given environment in such a way that,
when they are subsequently in a similar environment, they react
in a new way, but if similar environments recur often, the reaction
in the end becomes nearly uniform, while remaining different from
the reaction on the first occasion, (When I speak of the reaction
of a piece of matter to its environment, I am thinking both of the
constitution of the set of coinpresent events of which it consists,
and of the nature of the track in space-time which constitutes what
we should ordinarily call its motion; these are called a “reaction
to the environment” in so far as there are laws correlating them
with characteristics of the environment.) Out of habit, the peculiari-
ties of what we call “mind” can be constructed; a mind is a track
of sets of compresent events in a region of space-time where there
is matter which is peculiarly liable to form habits. The greater the
liability, the more complex and organized the mind becomes. Thus
a mind and a brain are not really distinct, but when we speak of a
mind we are thinking chiefly of the set of compresent events in the
region concerned, and of their several relations to other events form-
ing parts of other periods in the history of the spatio-temporal tube
which we are considering, whereas when we speak of a brain we

m

[ 50 ]

BERTRAND RUSSELL

compresent events as a whole, and considerinE
Its eternal relations to other sets of compresent events alS talcpf
^ wholes; m a word, we are considering the shape of the tube not
the events of which each cross-section of it is composed.

summary hypothesis would, of course, need to be
amplified and refined m many ways in order to fit in comoletelv

forward as a finished theo^ but
nf r ^ ^ suggestion of the kind of thing that may be true It is

of course easy to imagine other hypotheses which may be true for
example, the hypoteia that there is oothiag outsSfthe Ss 3

SSf m °® hypothesis, and therefore

rmraWSy-r^hTosS^^^ tItaTr

From time to time prizes have been established for essays on the
question what progress philosophy has made in a given period. The
period tends to be limited on the one side by the name of some great
thinker, on the other by ‘‘the present.’’ It was thus assumed that there
is some degree of clarity regarding the philosophic progress of man-
kind up to the time of that thinker, but that it is dubious what further
contributions have been made in recent times.

Such questions clearly express a certain mistrust concerning the
philosophy of the period which had recently elapsed. One has the
impression of being presented only with an embarrassed formulation
of the question: Has philosophy in that period made any progress
whatever? For if one were sure that contributions had been made one
would also know in what they consisted.

If the more remote past is regarded with less scepticism and
one is rather inclined to see in its philosophy a continuous devel-
opment, the explanation may be that one’s attitude towards every-
thing whose place is established in history is tinged with greater re-
spect. A further point is that the older philosophers have at least
demonstrated their historical influence. Hence in considering them
one can take as one’s base their historical rather than their substantive
importance, especially since one often does not venture to distinguish
between the two.

But it is just the ablest thinkers who most rarely have believed
that the results of earlier philosophizing, including that of the classical
models, remain unshakable. This is shown by the fact that basically
ever}' no^w system starts again from the beginning, that every thinker

“Die Wende Der Pliiiosophie,” as this piece is called in German, opened the
first number of Volume I of Brkenntnis (1930/31). It is here published with the
kind permission of Mrs. Schiick and Professor Carnap, the co-editor of Brkenntnis.

The Turning Point in Philosophy

BY MORITZ SCHLICK

(TRANSLATED BY DAVID RYNIN)

[ 53 ]

[ ] MORITZ SCHLICKI

seeks Ms own foundation and does not wish to stand on the shoul-
ders of his predecessors. Descartes (not without reason) felt himself
to be making a wholly new beginning; Spinoza believed that in
introducing the (to be sure quite adventitious) mathematical form
he had found the ultimate philosophical method; and Kant was
convinced that on the basis of the way taken by him philosophy
would at last adopt the sure path of a science. Further examples
are superfluous, for practically all great thinkers have sought for
a radical reform of philosophy and considered it essential.

TMs peculiar fate of philosophy has been so often described
and bemoaned that it is indeed pointless to discuss it at all. Silent
scepticism and resignation seem to be the only appropriate attitudes.
Two thousand years of experience seem to teach that efforts to put
an end to the chaos of systems and to change the fate of philosophy
can no longer be taken seriously. To point out that man has finally
succeeded in solving the most stubborn problems, for example that of
Daedelus, gives an informed person no comfort; for what he fears is
just that philosophy will never arrive at a genuine “problem.”

I refer to this anarchy of philosophical opinions which has so
often been described, in order to leave no doubt that I am fully con-
scious of the scope and weighty significance of the conviction that I
should now like to express. For 1 am convinced that we now find
ourselves at an altogether decisive turning point in philosophy, and
that we are objectively justified in considering that an end has come
to the fruitless conflict of systems. We are already at the present time,
in my opinion, in possession of methods which make every auch con-
flict in principle unnecessary. What is now required is their resolute
application.

These methods have been quietly developed, unnoticed by the
majority of those who teach or write philosophy; and thus a situation
has been created which is not comparable to any earlier one. That
the situation is unique and that the turning embarked upon is really
decisive can be understood only by becoming acquainted with the
new paths and by looking back, from the standpoint to which they
lead, upon all those efforts that have ever passed as “philosophiciii.”

The paths have their origin in logic. Leibniz dimly saw their
beginning. Bertrand Russell and Gottlob Frege have opened up im-
portant stretches in the last decades, but Ludwig Wittgenstein (in
his Tractatus Logico-Fhilosophicus, 1922) is the first to have pushed
forward to the decisive turning point.

It is well known that in recent decades mathematicians have
developed new logical methods, at first primarily for the solution

Turning Faint in Philosophy [ 55 ]

:“‘j\ ^ own problems wMcb could not be overcome by the tradi-
.'■''''"lional methods of logic. But the logic thus developed has also long
ginoe shown its superiority in other ways over the old forms, and
doubtless will very soon supplant them. Was I referring to this logic

" 25 ifje powerful means which is in principle capable of raising us above

‘ ‘ all philosophical coEflicts? Does it give us general rules with those
help aU the traditional problems of philosophy can at least in prin-
! ! ' ciple be 'resolved?

. , If tins were so I should hardly have had the right to say that a
wholly new situation had been created. For then there would have
been only a gradual, as it were, technical progress, as for example,
when the invention of the intemal combustion engine finally made
possible the solution of the problem of flight. However highly the
value of the new methods is to be esteemed, it is plain that nothing
so fundamental can be brought about by the mere development of
a method. The great turning point is therefore not to be attributed
to logic itself but to something quite difierent wiiich was indeed stim-
ulated and made possible by it, but which proceeds on a much
deeper level: the insight into the nature of logic itself.

That the logical is in some sense the purely formal has been
expressed early and often; however, one was not really clear con-
cerning the nature of pure forms. The clue to their nature is to be
found in the fact that every cognition is an expression or repre-
sentation. That is, it expresses a fact which is cognized in it. This
can happen in any number of ways, in any language, by means of
any arbitrary^ system of signs. All these possible modes of repre-
sentation — if they otherwise actually express the same knowledge —
must have something in common; and what is common to them is
their logical form.

So all knowledge is such only by virtue of its form. It is through
its form that it represents the fact known. But the form cannot itself
in turn be represented. It alone is concerned in cognition. Everything
else in the expression is inessential and accidental material, not
different, say, from the ink by means of which we write down a
statement.

This simple insight has consequences of the very greatest im-
portance. Above all, it enables us to dispose of the traditional prob-
lems of “the theory of knowledge.” Investigations concerning the
human “capacity for knowledge,” in so far as they do not become
part of psychology, are replaced by considerations regarding the
nature of expression, of representation, i.e. concerning every pos-
sible “language” in the most general sense of the term. Questions

[56 1

^ ^ MORITZ SCHLICR

regardmg the “vahdity and Umits of knowledge” disappear Everv-
thmg IS knowable which can be expressed, and this is the total
^bject matter concerning which meaningful questions can be raised
Ihere are consequently no questions which are in principle un-
answerable, no problems which are in principle insoluble. What
aye been considered such up to now are not genuine questions
but meaningless sequences of words. To be sure, they look like ques-
lons from the outside, since they seem to satisfy the customary rules
of grammar but in truth they consist of empty sounds, because they
ransgress the profound inner rules of logical syntax discovered by
the new analysis. ^

Wherever there is a meaningful problem one can in theory always
c,ive e path that leads to its solution. For it becomes evident that
giving this path coincides with the indication of its meanin». The
practical following out of this path may of course be hindered by
factual circumstances-by deficient human capacities, for example.

■ , ^ ^ verification in which the path to the solution finally ends

us alwip of the same sort: it is the occurrence of a definite fact tha't
IS confirmed by observation, by means of immediate experience. In
us manner^ the truth (or falsity) of even,- statement, of daily life
or science, ,s determined. There is thus no other testing and' cor-
roboration of truths e.xcept through observation and empirical science
Exeiy^ science, (m so far as we take tills word to refcr'to thccontent
and not to the human arrangements for arriving at it) is a system of
cognitions, that is, of true experiential statements. And the totaiitv
ol sciences, including the statements of daily life, is the system of
cognitions. There is, in addition to it, no domain of ^philo^yphical”
tniths. 1 hilosophy is not a system of statements: it is not a iience.

But what IS It then? Well, certainly not a science, but neverthc-

•itb‘dbrrh"f important tiiat it mav henceforth,

tritn th-i o' “ the Queen of the Sciences. For'it is nowhere
ynttwi. that the Queen of the Sciences must itself be a science The
great contemporaQ^ turning point is characterized bv the fact that
wc see in philosophy not a system of cognitions, but a'svstem of aciv
philosophy IS tluit activity through which the meaning of statements
IS revealed or determined. By means of philosophy ^statemenS Tre
explained by means of science they are verified. The latter is con-

Th ^ the truth of statements, the former with what they actually

hat in the last analysis its statements actually mean; the philo-
sophical activity of giving meaning is therefore the Alpha and Omega
of aU scientific knowledge. This was indeed correctly surmised when

Turning Point in Philosophy [ 57 J

■ it was saidi that philosophy supplied both the foundation and the
apex of the edifice of science. It was a mistake, however, to suppose
that the foundation was made up of “philosophical’' statements (the
statements of theory of knowledge), and crowned by a dome of
philosophical statements (called metaphysics).

It is easy to see that the task of philosophy does not consist in
asserting statements — that bestowing meaning upon statements can-
not be done in turn by statements. For if, say, I give the meaning
of my words through explanatoiv^ statements and definitions, that is
by help of other words, one must ask further for the meaning of
these words, and so on. This process cannot proceed endlessly. It
I always comes to an end in actual pointings, in exhibiting what is
I meant, thus in real acts; only these acts are no longer capable of,

: or in need of, further explanation. The final giving of meaning always
I takes place therefore, through deeds. It is these deeds or acts which
1 constitute philosophical activity.

“ It was one of the most serious errors of former times to have
I believed that the actual meaning and ultimate content was in turn
to be formulated in statements, and so was representable in cognitions.
This was the error of “metaphysics.'' The efforts of metaphysicians
were always directed upon the absurd end of expressing the content
of pure quality (the “essence" of things'! by means of cognitions,
hence of uttering the unutterable.'^ Qualities cannot be “said." They
can only be shown in experience. But with this showing, cognition has
nothing to do.

Thus metaphysics collapses not because the solving of its tasks
is an enterprise to which the human reason is unequal (as for ex-
ample Kant thought) but because there is no such task. With the
disclosure of the mistaken formuiaiion of the problem the histoiw
of metaphysical conflict is likewise explained.

If our conception is in general correct we must be able to establish
it historicaliy. It would have lo be capable of gffang some account
of the change in meaning of the word “philosophy."

Now this is actually the case. If in ancient times, and actually
until recently, philosophy was simply identical with eveiy^ purely
theoretical scientific investigation, this points to the fact that science
found itself in a state in which it saw its main task still in the clari-
' fication of its fundamental concepts. The emancipation of the special
sciences from their common mother, philosophy, indicates that the
' meaning of certain fundamental concepts became clear enough to
make successful further work with them possible. If, today, ethics

1. See my article “Erleben, Erkennen, Meiaphysik/’ Kantstudien, Vol. 31 (1930).

ist be able to establish
ai\anc some account

MORITZ SCHLICK

[ 58 ]

and aesthetics, and frequently also psychology, are considered branches
of philosophy, this is a sign that these studies do not yet possess
sufficiently clear basic concepts, that their efforts are still chieiy
directed upon the meaning of their statements. Finally, if within
a well-established science the necessity suddenly arises at some
point of reflecting anew on the true meaning of the fundamental
concepts, and thereby a more profound clarification of their mean-
ing is achieved, tins will be felt at once as an eminent philosophical
achievement. All are agreed that, for instance, Einstein’s work, pro-
ceeding from an analysis of the meaning of statements about time and
space, was actually a philosophical achievement. Here we should add
that the decisive epoch-making forward steps of science are always
of this character; they signify a clarification of the meaning of the
fundamental statements and only those succeed in them who are
endowed for philosophical activity. The great investigator is also
always a philosopher.

Frequently also the name of philosophy is bestowed on mental
activities which have as their concern not pure knowledge but the con-
duct of life. This is readily understandable. For the wise man rises
above the uncomprehending mass just by virtue of the fact that he
can point out more clearly than they the meaning of statements and
questions concerning life relationships, facts and desires.

The great turning point of philosophy signifies also a decisive
turning away from certain erroneous paths which have been embarked
upon since the second half of the 19 th century and which must lead
to quite a wrong assessment and evaluation of philosophy. I mean
the attempts to claim for it an inductive character and accordingly to
believe that it consists solely of statements of hypothetical validity.
The idea of claiming only probability for its statements was remote
from earlier thinkers. They would have rejected it as incompatible
with the dignity of philosophy. In this was expressed a healthy instinct
for the fact that philosophy must supply the ultimate support of knowl-
edge. The reverse side of the medal is the dogma that philosophy
supplies unconditionally true a priori axioms, which we must regard
as an extremely unfortunate expression of this instinct, particularly
since philosophy does not consist of statements at all. But we too be-
lieve in the dignity of philosophy and deem incompatible with it the
character of being uncertain and only probable; and we are happy that
the decisive turning point makes it impossible to attribute any such
character to it. For the concept of probability or uncertainty is simply
not applicable to the acts of giving meaning which constitute philos-
ophy. It is a matter of positing the meaning of statements as something

Tht\Turmng Point in Philosophy [ 59 ]

simply final. Either we have this meaning, and then we know what is
meant by the statement, or we do not possess it, in which case mere
empty words confront ns, and as yet no statement at all. There is noth-
ing in between and there can be no talk of the probability that the
meaning is the right one. Thus after the great turning point philosophy
shows its decisive character even more clearly than before.

It is only, indeed, because of this character that the conflict of
systems can be ended. I repeat: in consequence of the insights which
I have sketched we may today consider it as in principle already ended.
I hope that this may become increasingly clear in the pages of this
journal^ in the new period of its existence.

Certainly there will still be many a rear-guard action. Certainly
many will for centuries continue to wander further along the traditional
paths. Philosophical writers will long continue to discuss the old
pseudo-questions. But in the end they will no longer be listened to;
they will come to resemble actors who continue to play for some
time before noticing that the audience has slowly departed. Then
it will no longer be necessary to speak of “philosophical problems”
for one will speak philosophicaliy concerning all problems, that is:
clearly and meaninghiUy.

^ Sc. Erkenntnis, Ed.

3

The Elimination of Metaphysics
Through Logical Analysis

of Language
BY RUDOLF CARNAP
(translated by ARTHUR PAP)

1. Introduction

There have been many opponents of metaphysics from the Greek
skeptics to the empiricists of the 19th century'. Criticisms of very
diverse kinds have been set forth. Many have declared that the doc-
trine of metaphysics is false, since it contradicts our empirical knowl-
edge. Others have believed it to be uncertain, on the ground that its
problems transcend the limits of human knowledge. Many anti-
metaphysicians have declared that occupation with metaphysiciil ques-
tions is sterile. Whether or not these questions can be answered, it is at
any rate unnecessary^ to worry about them; let us devote ourselves
entirely to the practical tasks which confront active men every day
of their lives!

The development of modern logic has made it possible to give a
new and sharper answer to the question of the validity and justi-
fication of metaphysics. The researches of applied logic or the theory
of knowledge, which aim at clarifying the cognitive content of sci-
entific statements and thereby the meanings of the terms that occur
in the statements, by means of logical analysis, lead to a positive
and to a negative result. The positive result is worked out in the
domain of empirical science; the various concepts of the various
branches of science are clarified; their formal-logical and epistemo-
logical connections are made explicit. In the domain of metaphysics,

This artide, originally entitled *‘Uberwindung der Metaphysik durch Logische
Analyse der Sprache/’ appeared in Erkenntnis, Vol. H (1932). It is published here
with the kind permission of Professor Carnap.

[ 60 ]

the EUmination of Metaphysics [ 61 ]

'indiidiiig aH philosophy of value and normative theory, logical
analysis yields the negative result that the alleged statements in this
domain are entirely meaningless. Therewith a radical elimination of
metaphysics is attained, which was not yet possible from the earlier
antlmetaphysical standpoints. It is true that related ideas may be
found already in several earlier trains of thought, e.g. those of a
nominalistic jtind; but it is only now when the development of logic
during recent decades provides us with a sufficiently sharp tool that
the decisive step can be taken.

In saying that the so-called statements of metaphysics are mean-
ingless, we intend this word in its strictest sense. In a loose sense
of the word a statement or a question is at times called meaningless
if it is entirely sterile to assert or ask it. We might say this for in-
stance about the question ‘'what is the average weight of those inhabi-
tants of Vienna w^hose telephone number ends with ‘3’?” or about
a statement which is quite obviously false like “in 1910 Vienna had
6 inhabitants” or about a statement which is not just empirically,
but logically false, a contradictory statement such as “persons A
and B are each a year older than the other.” Such sentences are
really meaningful, though they arc pointless or false; for it is only
meaningful sentences that are even divisible into (theoretically) fruit-
ful and sterile, true and false. In the strict sense, however, a sequence
of words is meaningless if it does not. within a specified language,
constitute a statement. It may happen that such a sequence of words
looks like a statement at first glance; in that case we call it a pseudo-
statement. Our thesis, now, is that logical analysis reveals the alleged
statements of metaphysics to be pseudo-statements.

A language consists of a vocabulaiy' and a syntax, i.e. a set of
words which have meanings and rules of sentence formation. These
rules indicate how sentences may be formed out of the various sorts
of words. Accordingly, there are two kinds of pseudo-statements:
either they contain a w^ord which is erroneously believed to have
meaning, or the constituent words are meaningful, yet are put together
in a counter-symtactical w^ay, so that they do not yield a meaningful
statement. We shall show in terms of examples that pseudo-statements
of both kinds occur in metaphysics. Later we shall have to inquire
into the reasons that support our contention that metaphysics in its
entirety consists of such pseudo-statements.

2. The Significance of a Word

A word which (within a definite language) has a meaning, is
usually also said to designate a concept; if it only seems to have a

I «>^i

• 1 . RUDOLF CARNAP

Sn? r- “ -mnlo^nccpt.”

evere w„Si hSf ? . Ps/udo^ncept to be explained? Has TOt

guage contain meaningless word<:‘? To hf> c, ’ traditional Ian-
(ex«pdn. rate cases whi^ iS:-,a“.eS”S Se

£ meaSTAnd > word freqnen.^"S5;

sense without t^u a* Omes that a word loses its old

arises. ^ ^ ^ pseudo-concept

S Sn:fbe”Zj?in“'ordeTg;

ex^L^yfaM'do™ TiT'SeTase” f"''''*'’" ••>-

Modern science, or X XX 2

ot the word°LM'brfi2d°Vr'thf”** riret, the syntax

simplest sentence fnrm ; ^ts occurrence in the

this entenS forl occurring; we call

form for th? worf is ?' Is““',

♦ . ^'cr>* X is <1 stone I m sentences nf thtc

place of™V’^e?^^?v category of things occupies the

pxace ot X, e.g. this diamond,” “this apnle ” Sernndiv fmr-

SThe°fo2,w““°“ ^ “"‘“”‘"6 «>' word an'^answe, mn, V° ven
(I m7sf ,“"™' fortPolated in varied w"^s

ere dedneS frS ““

wha[ wndMoS Se?“"‘“‘'°"' “ ® “ I-' “"*r

(3.) How is S to be verifiedl
(4.) What is the meaning of S'^

knowledge (4) with"th«P«f ?, ^ Phraseology of the theoiy of

ae •WtaTS’" f ‘ th-coTSn ( a , t

tSedTxpisS “ P'ooo'tf to give elsewhere a dl

i.e. relatims of dedudSii,?T “ ““

wheL:^'mTorSSS'S?f I '"oSL'-S T-

Ptoanntg by rednetion to other wori cSro^TSnT

■■ of Metaphysics [ 63 ]

E.g. ‘“‘arthropodes’ are animals with segmented bodies and jointed
legs.” Thereby the above-mentioned question for the elementary sen-
tence form of the word ‘"arthropode,” that is for the sentence form
‘"the thing x is an arthropode,” is answered: it has been stipulated
that a sentence of this form is deducible from premises of the form
“x is an animal,” ‘‘x has a segmented body,” '‘x has jointed legs,”
and that conversely each of these sentences is deducible from the
former sentence. By means of these stipulations about deducibility
(in other words: about the truth-condition, about the method of veri-
fication, about the meaning) of the elementary sentence about "'arthro-
pode” the meaning of the word “arthropode” is fixed. In this way
every word of the language is reduced to other words and finally to
the words which occur in the so-called "‘observation sentences” or
“protocol sentences.” It is through this reduction that the w^ord
acquires its meaning.

For our piiqi^oses we may ignore entirely tlie question concerning
the content and form of the primary sentences (protocol sentences)
which has not yet been definitely settled. In the theory of knowledge
it is customary to say that the primary sentences refer to “the given”;
but there is no unanimity on the question what it is that is given. At
times the position is taken that sentences about the given speak of the
simplest qualities of sense and feeling (e.g. “wami,” “blue,” “joy”
and so forth); others incline to the view that basic sentences refer to
total experiences and simiiarities between them; a still diflercnt
view has it that even the basic sentences speak of things. Regardless
of this diversity of opinion it is certain that a sequence of words has
a meaning only if its relations of deducibility to the protocol sen-
tences are fixed, whatever the characteristics of the protocol sen-
tences may be; and similarly, that a word is significant only if the
sentences in which it may occur are reducible to protocol sentences.

Since the meaning of a word is determined by its criterion of
application (in other words: by the relations of deducibility entered
into by its elementary sentence-form, by its truth-conditions, by
the method of its verification), the stipulation of the criterion takes
away one’s freedom to decide what one wishes to “mean” by the
word. E the word is to receive an exact meaning, nothing less than
the criterion of application must be given; but one cannot, on the
other hand, give more than the criterion of application, for the
latter is a sufficient determination of meaning. The meaning is im-
plicitly contained in the criterion; all that remains to be done is to
make the meaning explicit.

Let us suppose, by way of illustration, that someone invented

I 64 ] RUDOLF CARNAP

the new word “teavy” and maintained that there are things which
are teavy and things which are not teavy. In order to learn the
meaning of this word, we ask him about its criterion of application:
how is one to ascertain in a concrete case whether a given thing is
teavy or not? Let us suppose to begin with that we get no answer
from him: there are no empirical signs of teavyness, he says. In
that case we would deny the legitimacy of using this word. If the
person who uses the word says that all the same there are things
which are teavy and there are things which are not teavy, only it
remains for the weak, finite intellect of man an eternal secret which
things are teavy and which are not, we shall regard this as empty
verbiage. But perhaps he will assure us that he means, after all,
something by the word “teavy.” But from this we only learn the
psychological fact that he associates some kind of images and feel-
ings with the word. The word does not acquire a meaning through
such associations. If no criterion of application for the word is
stipulated, then nothing is asserted by the sentences in which it
occurs, they are but pseudo-statements.

Secondly, take the case when we are given a criterion of appli-
cation for a new word, say “toovy”; in particular, let the sentence
“this thing is too\y” be true if and only if the thing is quadrangular (It
is irrelevant in this context whether the criterion is '"explicitly 'stated
or whether we derive it by observing the affirmative and the nega-
tive uses of the word). Then we will say: the word “tooyj^” is synon-
ymous with the word “quadrangular.” And we will not allow its
users to tell us that nevertheless they “intended” something else by
it than “quadrangular”; that though every quadrangular thing is also
toov>' and conversely, this is only because quadrangularity is the
visible manifestation of toovyness, but that the latter itself is a
hidden, not itself observable property. We would reply that after
the criterion of application has been fixed, the synonymy of “toovy”
and “quadrangular” is likewise fixed, and that we are no further
at liberty to “intend” this or that by the word.

Let us briefly summarize the result of our analysis. Let “a” be
any word and “S(a)” the elementary sentence in which it occurs.
Then the sufficient and necessary condition for “a” being meaningful
may be given by each of the following formulations, which ulti-
mately say the same thing:

1. The empirical criteria for a are known.

2. It has been stipulated from what protocol sentences “S(a)”
is deducihle.

” EUmxnation of Metaphysics

3, The truth-conditions for “S(a)” are fixed.

4, The method of verification of “S(a)” is known.^

[65]

3. Metaphysical Words Without Meaning

Many words of metaphysics, now, can be shown not to fulfill the
atx 5 ve requirement, and therefore to be devoid of meaning.

Let us take as an example the metaphysical term ‘"principle”
(in the sense of principle of being, not principle of knowledge or
axiom). Various metaphysicians offer an answer to the question
which is the (highest) “principle of the world” (or of “things,” of
“existence,” of “being”), e.g. water, number, form, motion, life, the
spirit, the idea, the unconscious, activity, the good, and so forth. In
order to discover the meaning of the word “principle” in this meta-
physical question we must ask the metaphysician under what con-
ditions a statement of the form “x is the principle of y” would be
true and under what conditions it would be false, in other words:
we ask for the criteria of application or for the definition of the word
“principle.” The metaphysician replies approximately as follows:
“x is the principle of y” is to mean “y arises out of x,” “the being
of y rests on the being of x,” “y exists by virtue of x” and so forth.
But these words are ambiguous and vague. Frequently they have a
clear meaning; e.g., we say of a thing or process y that it “arises out
of’ X when we observe that things or processes of kind x arc fre-
quently or invariably followed by things or processes of kind y (causal
connection in the sense of a lawful succession). But the metaphysician
tells us that he does not mean this empirically observable relationship.
For in that case his metaphysical theses would be merely empirical
propositions of the same kind as those of physics. The expression
“arising from” is not to mean here a relation of temporal and causal
sequence, which is what the word ordinarily means. Yet, no criterion
is specified for any other meaning. Consequently, the alleged “meta-
physical” meaning, which the word is supposed to have here in con-
trast to the mentioned empirical meaning, does not exist. If we
reflect on the original meaning of the word “principium” (and of the
corresponding Greek word apx^^), we notice the same development.
The word is explicitly deprived of its original meaning “beginning”;
it is not supposed to mean the temporally prior any more, but the
prior in some other, specifically metaphysical, respect. The criteria
for this “metaphysical respect,” however, are lacking. In both cases,

1. For the logical and epistemological conception which underlies our exposition,
but can only briefly be intimated here, cf. Wittgenstein, Tractatus Logico-Philoso-
pkicus, 1922, and Carnap, Der logische Aufbau der Welt, 1928.

f 3 RUDOLF CARNAP

then, the word has been deprived of its earlier meaning without bem<r
given a new meaning; there remains the word as an empty shell. From
an earlier period of significant use, it is still associatively connected
with various mental images; these in turn get associated with new
mental images and feelings in the new context of usage. But the word
does not thereby become meaningful; and it remains meaningless
as long as no method of verification can be described.

AnoAer example is the word “God.” Here we must, apart from
the variations of its usage within each domain, distinguish the
linguistic usage in three different contexts or historical epochs, which
how:iver overlap temporally. In its mythological use the word has
a clear meaning. It, or parallel words in other languages, is some-
dmes used to denote physical beings which are enthroned on Mount
Olympus, in Heaven or in Hades, and which are endowed with
power, wisdom, goodness and happiness to a greater or lesser extent.
Sometimes the word also refers to spiritual beings which, indeed^
do not have manlike bodies, yet manifest themselves nevertheless’
somehow m the things or processes of the visible world and are
therefore empirically verifiable. In its metaphysical use, on the other
hand, the word “God” refers to something beyond experience. The
word is deliberately divested of its reference to a physical being or to
a spiritual being that is immanent in the physical. And as it is not
given a new meaning, it becomes meaningless. To be sure, it often
lookj as though the word God had a meaning even in metaphysics.
But the definitions which are set up prove on closer inspection to be
pseudo-definitions. They lead either to logicaUy illegitimate combina-
tions of words (of which we shall treat later) or to other meta-
physical words (e.g. “primordial basis,” “the absolute,” “the uncon-
ditioned,” “the autonomous,” “the self-dependent” and so forth),
but in no case to the truth-conditions of its elementary sentences.’
In the case of this word not even the first requirement of loaic is met,
that is the requirement to specify its sy^ntax, i.e. the form of its
occurrence in elementary sentences. An elementary sentence would
hvre have to be of the form x is a God”; yet, the metaphysician
either rejects this form entirely without substituting another, or if
he accepts it he neglects to indicate the syntactical category 'of the
variable x. (Categories are, for example, material things, properties
of things, relations between things, numbers etc.).

The theological usage of the word “God” falls between its mytho-
logical and its metaphysical usage. There is no distinctive meaning
here, but an oscillation from one of the mentioned two uses to the
other. Several theologians have a clearly empirical (in our termin-

- 'fhe''Bimlnation of Metaphysics [ 67 ]

ology, ‘^mytliologicar’) concept of God. In this case there are no
psendo-statements; but the disadvantage for the theologian lies in
the circumstance that according to this interpretation the statements
of theology are empirical and hence are subject to the judgment of
empirical science. The linguistic usage of other theologians is clearly
metaphysical. Others again do not speak in any definite way, whether
this is because they follow now this, now that linguistic usage, or
because they express themselves in terms whose usage is not clearly
classifiable since it tends towards both sides.

Just like the examined examples ‘"principle” and ""God,” most of
the other specifically metaphysical terms are devoid of meaning, e.g.
“the Idea,” “the Absolute,” ""the Unconditioned,” “the Infinite,”
“the being of being,” “non-being,” "‘thing in itself,” “absolute spirit,”
“objective spirit,” “essence,” “being-in-itself,” “being-in-and-for-
itseif,” “emanation,” “manifestation,” “articulation,” “the Ego,”
“the non-Ego,” etc. These expressions are in the same boat with
“teavy,” our previously fabricated example. The metaphysician tells
us that empirical truth-conditions cannot be specified; if he adds that
nevertheless he “means” something, we know that this is merely an
allusion to associated images and feelings which, however, do not
bestow a meaning on the word. The alleged statements of meta-
physics which contain such words have no sense, assert nothing, are
mere pseudo-statements. Into the explanation of their historical origin
we shall inquire later.

4. The Significance of a Sentence

So far we have considered only those pseudo-statements which
contain a meaningless word. But there is a second kind of pseudo-
statement. They consist of meaningful words, but the words are put
together in such a way that nevertheless no meaning results. The
syntax of a language specifies which combinations of words are
admissible and which inadmissible. The grammatical syntax of
natural languages, however, does not fulfill the task of elimination of
senseless combinations of words in all cases. Let us take as examples
the following sequences of words:

1. “Caesar is and”

2. “Caesar is a prime number”

The word sequence (1) is formed countersyntacticaliy; the rules
of syntax require that the third position be occupied, not by a
conjunction, but by a predicate, hence by a noun (with article) or by
an adjective. The word sequence “Caesar is a general,” e.g., is

[ 68 ] , RUDOLF CARNAP

formed in accordance with the rules of syntax. It is a meaningful
word sequence, a genuine sentence. But, now, word sequence (2) is
Ekewise syntactically correct, for it has the same grammatical form as
the sentence just mentioned. Nevertheless (2) is meaningless. ‘Trime
number” is a predicate of numbers; it can be neither affirmed nor
denied of a person. Since (2) looks Eke a statement yet is not a
statement, does not assert anything, expresses neither a true nor a
false proposition, we call this word sequence a '‘pseudo-statement.”
The fact that the rules of grammatical syntax are not violated easEy
seduces one at first glance into the erroneous opinion that one still
has to do with a statement, albeit a false one. But “a is a prime
number” is false if and only if a is divisible by a natural number
different from a and from 1 ; evidently it is Elicit to put here "Caesar”
for "a.” This example has been so chosen that the nonsense is
easily detectable. Many so-caEed statements of metaphysics are not
so easily recognized to be pseudo-statements. The fact that natural
languages allow the formation of meaningless sequences of words
without violating the rules of grammar, indicates that grammatical
syntax is, from a logical point of view, inadequate, li grammatical
syntax corresponded exactly to logical syntax, pseudo-statements could
not arise. If grammatical syntax differentiated not only the word-
categories of nouns, adjectives, verbs, conjunctions etc., but within
each of these categories made the funher distinctions that are
logically indispensable, then no pseudo-statements could be formed.
If, e.g., nouns were grammatically subdivided into several kinds of
words, according as they designated properties of physical objects,
of numbers etc., then the words "general” and ‘"prime number”
would belong to grammatically different word-categories, and (2)
would be just as linguistically incorrect as (1). In a correctly con-
structed language, therefore, all nonsensical sequences of words
would be of the kind of example (1). Considerations of grammar
would already eliminate them as it were automatically; i.e. in order
to avoid nonsense, it would be unnecessary to pay attention to
the meanings of the individual words over and above their syn-
tactical type (their "syntactical category^” e.g. thing, property
of things, relation betw^een things, number, property of numbers,
relation between numbers, and so forth). It foEows that if our
thesis that the statements of metaphysics are pseudo-statements
is justifiable, then metaphysics could not even be expressed in a
logically constructed language. This is the great phEosophical im-
portance of the task, which at present occupies the logicians, of
building a logical syntax.

Jhe Elimination of Metaphysics [ 69 ]

5, Metaphysical Pseudo-statements

Let us now take a look at some examples of metaphysical pseudo-
statements of a kind where the violation of logical syntax is especially
obvious, though they accord with historical-grammatical syntax. We
select a few sentences from that metaphysical school which at present
exerts the strongest influence in Germany.^

“What is to be investigated is being only and — nothing else;
being alone and further — nothing; solely being, and beyond being —
nothing. What about this Nothing? . . . Does the Nothing exist only
because the Not, i.e. the Negation, exists? Or is it the other way
around? Does Negation and the Not exist only because the Nothing
exists? . . . We assert: the Nothing is prior to the Not and the Nega-
tion. . . , Where do we seek the Nothing? How do we find the
Nothing. . . . We know the Nothing. . . . Anxiety reveals the Nothing.

. . . That for which and because of which we were anxious, was
‘really’ — nothing. Indeed: the Nothing itself — as such — was present,

. . . What about this Nothing? — The Nothing itself nothings^

In order to show that the possibility of forming pseudo-statements
is based on a logical defect of language, wc set up the schema bclow^
The sentences under I are grammatically as well as logically im-
peccable, hence meaningful. The sentences under II (excepting B3)
are in grammatical respects perfectly analogous to those under I,
Sentence form 11 A (as question and answer) does not, indeed, satisfy
the requirements to be imposed on a logically correct language. But
it is nevertheless meaningful, because it is translatable into correct
language. This is shown by sentence IIIA, which has the same mean-
ing as IIA. Sentence form JIA then proves to be undesirable because
w^e can be led from it, by means of grammatically faultless operations,
to the meaningless sentence forms IIB, which are taken from the
above quotation. These forms cannot even be constructed in the
correct language of Column HI. Nonetheless, their nonsensicality is
not obvious at first glance, because one is easily deceived by the
analogy with the meaningful sentences IB. The fault of our language
identified here lies, therefore, in the circumstance that, in contrast
to a logically correct language, it admits of the same grammatical
form for meaningful and meaningless word sequences. To each
sentence in words we have added a corresponding formula in the

2. The following quotations (original italics) are taken from M. Heidegger,
Was 1st Metaphysik? 1929. We could just as well have selected passages from any
other of the numerous metaphysicians of the present or of the past; yet the selected
passages seem to us to illustrate our thesis especially well.

r ^ RUDOLF CARNAP

notation of symbolic logic; these formulae facilitate recoanition of
the undesirable analogy between lA and HA and therewTth of the
origin of the meaningless constructions HB.

/.

Meaningful
Sentences of
Ordinary
Language

A. What is outside?

Ou(?)

Rain is outside

Ou(r)

n.

Transition from
Sense to
Nonsense in
Ordinary
Language

A. What is outside?

Ou(?)

Nothing is outside
Ou(no)

111 ,

Logically

Correct

Language

A. There is nothing
(does not exist any-
thing) which is
outside.

-^(Hx) .Ou(x)

B. What about this rain?
(i.e. what does the
rain do? or: what
else can be said
about this rain?

?(r)

B. “What about this
Nothing?” ?(no)

B. None of these fonns
can even be
constructed.

I. W^e know the rain 1. “We seek the
K(r) Nothing”

“We find the
Nothing”
“We know the
Nothing”

K(no)

2. “The Nothing
nothings”

No(no)

3. “The Nothing
exists only
because . . .”

Ex(no)

On closer inspection of the pseudo-statements under IIB, w^e also
find some differences. The construction of sentence (1) is simply
based on the mistake of employing the word “nothing” as a noun,
because it is customary in ordinary language to use it in this form in
order to construct a negative existential statement (see HA). In
a correct language, on the other hand, it is not a particular name
but a certain logical form of the sentence that serves this purpose

2. The rain rains
R(r)

> . The Elimination of Metaphysics [ M

(see IIIA). Sentence IIB2 adds something new, viz. the fabrication
of the meaningless word “to nothing.” This sentence, therefore, is
senseless for a twofold reason. We pointed out before that the mean-
ingless words of metaphysics usually owe their origin to the fact
that a meaningfui word is deprived of its meaning through its meta-
phorical use in metaphysics. But here we confront one of those rare
cases where a new word is introduced which never had a meaning
to begin with. Likewise sentence IIB3 must be rejected for two rea-
sons. In respect of the error of using the word “nothing” as a noun,
it is like the previous sentences. But in addition it involves a contra-
diction. For even if it were admissible to introduce “nothing” as
a name or description of an entity, still the existence of this entity
would be denied in its very definition, whereas sentence (3) goes on
to affirm its existence. This sentence, therefore, would be contradic-
tory, hence absurd, even if it were not already meaningless.

In view of the gross logical errors which we find in sentences
IBB, we might be led to conjecture that perhaps the word “nothing”
has in Heidegger’s treatise a meaning entirely different from the
customary one. And this presumption is further strengthened as we
go on to read there that anxiety reveals the Nothing, that the Nothing
itself is present as such in anxiety. For here the word “notliing” seems
to refer to a certain emotional constitution, possibly of a religious
sort, or something or other that underlies such emotions. If such
were the case, then the mentioned logical errors in sentences IIB
would not be committed. But the first sentence of the quotation
at the beginning of this section proves that this interpretation is not
possible. The combination of “only” and “nothing else” shows un-
mistakably that the word “nothing” here has the usual meaning of
a logical particle that sei*ves for the formulation of a negative exis-
tential statement. This introduction of the word “nothing” is then
immediately followed by the leading question of tlie treatise: “What
about this Nothing?”.

But our doubts as to a possible misinterpretation get completely
dissolved as we note that the author of the treatise is clearly aware
of the conflict between his questions and statements, and logic.
''Question and answer in regard to the Nothing are equally absurd
in themselves. . . . The fundamental rule of thinking commonly
appealed to, the law of prohibited contradiction, general logic/
destroys this question.” All the worse for logic! We must abolish its
sovereignty: “If thus the power of the understanding in the field of
questions concerning Nothing and Being is broken, then the fate of
the sovereignty of logic’ within philosophy is thereby decided as

RUDOLF CARNAP

[ 72 ]

well. The vtry idea of ‘logic’ dissolves in the whirl of a more basic
qiiestioning.” But will sober science condone the whirl of counter-
logical questioning? To this question too there is a ready answer:
‘"The alleged sobriety and superiority of science becomes ridiculous
if it does not take the Nothing seriously.” Thus we find here a good
confirmation of our thesis; a metaphysician himself here states that
his questions and answers are irreconcilable with logic and the sci-
entific way of thinking.

The difference between our thesis and that of the earlier anti-
fnetaphysicians should now be clear. We do not regard metaphysics
as “mere speculation” or “fairy tales.” The statements of a fair\^
tale do not conflict with logic, but only with experience; they are
perfectly meaningful, although false. Metaphysics is not ''supersti-
tion”; it is possible to believe true and false propositions, but not
to believe meaningless sequences of v^ords. Metaphysical statements
are not even acceptable as "working hypotheses"; for an h}'pothesis
must be capable of .entering into relations of deducibility with (true
or false) empirical statements, which is just what pseudo-statements
cannot do.

With reference to the so-called limitation of hmnan knowledge
an attempt is sometimes made to save metaphysics by raising the
following objection: metaphysical statements are not. indeed, veri-
fiable by man nor by any other finite being; nevertli^less they might
be construed as conjectures about the answers which a being with
higher or even perfect powers of knowledge would make to our
cjuestions, and as such conjectures they would, after all, be mean-
ingful. To counter this objection, let us consider the following. If
the meaning of a word cannot be specified, or if the sequence of
words does not accord with the rules of syntax, then one has not
even asked a question. {'Just think of the pesudo-quesnons: "Is this
table teavy?”, “is the number 7 holy?”, “which numbers are darker,
the even or the odd ones?”). Where there is no quesiion, not even
an omniscient being can give an answer. Now the objecior may say:
jnst as one who can see may communicate new knowledge to the
blind, so a higher being might perhaps communicate to us meta-
physical knowledge, e.g. whether the visible world is the manifesta-
tion of a spirit. Here we must reflect on the meaning of “new knowl-
edge,” It is, indeed, conceivable that we might encounter animals
who tell us about a new sense. If these beings were to prove to us
Fermat’s theorem or were to invent a new physical instrument or
were to establish a hitherto unknown law of nature, then our knowl-
edge would be increased with their help. For this son of thing we

pl0:

The Elimination of Metaphysics [ ]

' can test, jnst the way even a blind man can understand and test the
whole of physics (and therewith any statement made by those who
can see). But if those hypothetical beings tell us something which
we cannot verify, then we cannot understand it either; in that case
no information has been communicated to us, but mere verbal sounds
devoid of meaning though possibly associated with images. It fol-
lows that our knowledge can only be quantitatively enlarged by
other beings, no matter whether they know more or less or every-
thing, but no knowledge of an essentially different kind can be
added. What we do not know for certain, we may come to know with
greater certainty through the assistance of other beings; but what
is unintelligible, meaningless for us, cannot become meaningful
through someone else’s assistance, however vast his knowledge might
be. Therefore no god and no devil can give us metaphysical knowledge.

6. Meaninglessness of ai.l Metaphysics

The examples of metaphysical statements which we have anal-
yzed were all taken from just one treatise. But our results apply with
equal validity, in part even in verbally identical ways, to other meta-
physical systems. That treatise is completely in the right in citing
approvingly a statement by Hegel (“pure Being and pure Nothing,
therefore, are one and the same”). The metaphysics of Hegel has
exactly the same logical character as this modern system of meta-
physics. And the same holds for the rest of the metaphysical systems,
though the kind of phraseology and therewith the kind of logical
errors that occur in them deviate more or less from the kind that
occurs in the examples we discussed.

It should not be necessary^ here to adduce further examples of
specific metaphysica! sentences in diverse systems and submit them
to analysis. Wc confine ourselves to an indication of the most fre-
quent kinds of errors.

Perhaps the majority of the logical mistakes that are committed
when pseudo-statements are made, are based on the logical faults
infecting the use of the word “to be” in our language (and of the
corresponding words in other languages, at least in most European
languages). The first fault is the ambiguity of the word “to be.” It
is sometimes used as copula prefixed to a predicate (“I am hungry”),
sometimes to designate existence (‘T am”). This mistake is ag-
gravated by the fact that metaphysicians often are not clear about
this ambiguity. The second fault lies in the form of the verb in its
second meaning, the meaning of existence. The verbal form feigns

RUDOLF CARNAP

^ ]

% v'® where there is none. To be sure, it has been known for

that existence is not a property (cf. Kant’s refutation
proof of the existence of God). But it was not
^ ^ modem logic that full consistency on this point

the syntactical form in which modern logic introduces

existence is such that it cannot, like a predicate, be ap-

^igns for objects, but only to predicates (cf. e.g. sentence
V above table). Most metaphysicians since antiquity have
themselves to be seduced into pseudo-statements by the
c ^ therewith the predicative form of the word “to be,” e.g.

>od is.”

f \ illustration of this error in Descartes’ “cogito, ergo

ijts disregard here the material objections that have been
^inst the premise — viz. whether the sentence “I think” ade-

5

th(x

"^^presses the intended state of affairs or contains perhaps an

-and consider the tvv'o sentences only from the formal-

witnoui preaicate; maeea, uescanes' ”i am ' nas always
th^ in this sense. But in that case this sentence violates

^^■'tnentioned logical mle that existence caii be predicated
^^junction with a predicate, not in conjunction with a name
' proper name) ' • . ^ .

of view. We notice at once two essential logical mis-
first lies in the conclusion “I am.” The verb “to be” is
fflly meant in the sense of existence here; for a copula can-
without predicate; indeed, Descartes’ “I am” has always

An existential statement does not have

exists” (as in “I am,” i.e. “I exist”), but “there exists
K of such and such a kind.” The second error lies in the

^5?^\w^^from ‘T think” to ‘T exist.” If from the statement “F(a)”

property P”) an existential statement is to be deduced,

V \ \ l^^tter can assert existence only with respect to the predicate
respect to the subject a of the premise. What follows
. a European” is not “I exist,” but “a European exists.”
from “I think” is not “I am” but “there exists some-
^^^'^Uhinks.”

Circumstance that our languages express existence by a verb
“to exist”) is not in itself a logical fg

Col

''hie

lav^

;Ot

fault; it is only inap-

dangerous. The verbal form easily misleads us into the

^v^l^tion that existence is a predicate. One then arrives at such

^ V ^correct and hence senseless modes of expression as were

a ^ J T t_ £ CeXT_x TTV-* _ »

Nned. Likewise such forms as “Being” or “Not-Being,’

time immemorial have played a great role in metaphysics,
^ame origin. In a logically correct language such forms can-

constructed. It appears that in the Latin and the German

-'The Bimnation of Metaphysics [ ]

/*' laliigiiages the forms “ens” or ‘‘das Seiende” were, perhaps under the
seductive influence of the Greek example, introduced specifically for
BSC by metaphysicians; in this way the language deteriorated logically
whereas the addition was believed to represent an improvement.

Another very frequent violation of logical syntax is the so-called
*'type confusion"' of concepts. While the previously mentioned mis-
take consists in the predicative use of a symbol with non-predicative
meaning, in this case a predicate is, indeed, used as predicate yet as
predicate of a different type. We have here a violation of the rules
of the so-called theory of types. An artificial example is the sentence
we discussed earlier: “Caesar is a prime number.” Names of persons
and names of numbers belong to different logical types, and so do
accordingly predicates of persons (e.g. “general”) and predicates of
numbers (“priine number”). The error of type confusion is, unlike
the previously discussed usage of the verb “to be,” not the preroga-
tive of metaphysics but already occurs veiy often in conversational
language also. But here it rarely leads to nonsense. The typical
ambiguity of words is here of such a kind that it can be easily removed.

Example: 1. “Tnis table is larger than that.” 2. “The height of this table
is larger than the height of that table.” Here the word “larger” is used in
(1) for a relation bervveen objects, in (2) for a relation between num-
bers, hence for two distinct syntactical categories. The mistake is
here unimportant; it could, e.g., be eliminated by writing “larger!” and
“larger2”; “largerl” is then defined in terms of “larger2” by declaring
statement form (1 » to be synonymous with (2) (and others of a similar
kind).

Since the confusion of types causes no harm in conversational
language, it is usually ignored entirely. This is, indeed, expedient for
the ordinar}’ use of language, but has had unfortunate consequences
in metaphysics. Here the conditioning by everyday language has led
to confusions of types which, unlike those in everyday language, are
no longer translatable into logically correct form. Pseudo-statements
of this kind are encountered in especially large quantity, e.g., in the
writings of Hegel and Heidegger. The latter has adopted many pe-
culiarities of the Hegelian idiom along with their logical faults (e.g.
predicates which should be applied to objects of a certain sort are
instead applied to predicates of these objects or to “being” or to
“existence” or to a relation between these objects).

Having found that many metaphysical statements are meaning-
less, we confront the question whether there is not perhaps a core
of meaningful statements in metaphysics which would remain after
elinmiation of all the meaningless ones.

RUDOLF CARNAP

[76]

Indeed, the results we have obtained so far might give rise to
the view that there are many dangers of falling into nonsense in
metaphysics, and that one must accordingly endeavor to avoid these
traps with great care if one wants to do metaphysics. But actually
the situation is that meaningful metaphysical statements are impos-
sible. This follows from the task which metaphysics sets itself: to
discover and formulate a kind of knowledge which is not accessible
to empirical science.

We have seen earlier that the meaning of a statement lies in the
method of its verification. A statement asserts only so much as is
verifiable with respect to it. Therefore a sentence can be used only
to assert an empirical proposition, if indeed it is used to assert any-
thing at all. If something were to lie, in principle, beyond possible
experience, it could be neither said nor thought nor asked,

(Meaningful) statements are divided into the following kinds.
First there are statements which are true solely by virtue of their
form ('‘tautologies” according to Wittgenstein; they correspond ap-
proximately to Kant’s “analytic judgments”). They say nothing
about reality. The formulae of logic and mathematics are of this
kind. They are not themselves factual statements, but serve for the
transformation of such statements. Secondly there are the negations of
such statements {''contradictions''). They are self-contradictory,
hence false by virtue of their form. With respect" to all other state-
ments the decision about truth or falsehood lies in the protocol sen-
tences. They are therefore (true or false) empirical statements and
belong to the domain of empirical science. Any statement one desires
to construct which does not fall within these categories becomes
automatically meaningless. Since metaphysics does not want to assert
analytic propositions, nor to fall within the domain of empirical
science, it is compelled to employ words for which no criteria of
application are specified and which are therefore devoid of sense,
or else to combine meaningful words in such a way that neither an
analytic (or contradictory) statement nor an empirical statement is
produced. In either case pseudo-statements are the inevitable product.

Logical analysis, then, pronounces the verdict of meaningless-
ness on any alleged knowledge that pretends to reach above or behind
experience. This verdict hits, in the first place, any speculative meta-
physics, any alleged knowledge by pure thinking or by pure intuition
that pretends to be able to do without experience. But the verdict
equally applies to the kind of metaphysics which, starting from ex-
perience, wants to acquire knowledge about that which transcends
experience by means of special inferences (e.g, the neo-vitalist thesis

'''Yhe Elimination of Metaphysics [ 77 ]

of the directive presence of an “entelechy" in organic processes, which
supposedly cannot be understood in terms of physics; the question
concerning the ‘'essence of causaiity/' transcending the ascertain-
ment of certain regularities of succession; the talk about the ‘‘thing
in itself’). Further, the same judgment must be passed on all philos-
ophy of norms, or philosophy of value, on any ethics or esthetics as
a normative discipline. For the objective validity of a value or norm
is (even on the view of the philosophers of value) not empirically
verifiable nor deducible from empirical statements; hence it cannot
be asserted (in a meaningful statement) at aD. In other words: Either
empirical criteria are indicated for the use of ‘‘good” and “beauti-
ful” and the rest of the predicates that are employed in the normative
sciences, or they are not. In the first case, a statement containing
such a predicate turns into a factual judgment, but not a value judg-
ment; in the second case, it becomes a pseudo-statement. It is alto-
gether impossible to make a statement that expresses a value judgment.

Finally, the verdict of meaninglessness also hits those meta-
physical movements which are usually called, improperly, epistemo-
logical movements, that is realism (insofar as it claims to say more
than the empirical fact that the sequence of events exhibits a certain
regularity, which makes the application of the inductive method pos-
sible) and its opponents: subjective idealism, solipsism, phenomenal-
ism, and positivism (in the earlier sense).

But what, then, is left over for philosophy, if all statements what-
ever that assert something are of an empirical nature and belong to
factual science? What remains is not statements, nor a theory, nor
a system, but only a method: the method of logical analysis. The
foregoing discussion has illustrated the negative application of this
method: in that context it serves to eliminate meaningless words,
meaningless pseudo-statements. In its positive use it serves to clarify
meaningful concepts and propositions, to lay logical foundations for
factual science and for mathematics. The negative application of the
method is necessar}' and important in the present historical situation.
But even in its present practice, the positive application is more
fertile. We cannot here discuss it in greater detail. It is the indicated
task of logical analysis, inquir}^ into logical foundations, that is meant
by ''scientific philosophy'' in contrast to metaphysics.

The question regarding the logical character of the statements
which we obtain as the result of a logical analysis, e.g. the state-
ments occurring in this and other logical papers, can here be an-
swered only tentatively: such statements are partly analytic, partly
empirical. For these statements about statements and parts of state-

if

■■ 'I i'i'

lii I

jli !

[ 78 ] RUDOLF CARNAP

ments belong in pure metalogic (e.g. “a sequence consisting

of the existence-sy^^t>oi and a noun, is not a sentence”), in part
to descriptive word sequence at such and such

a place in such aXtd such a book is meaningless”). Metalogic will
be discussed eisewb^^^- ^Iso be shown there that the metalogic

wiiich speaks about the sentences of a given language can be for-
mulated in that vety language itself.

7. Metaphysi<7^ Expression of

AN Attitude toward Life

Our claim that the statements of metaphysics are entirely mean-
ingless, that they do not assert anything, will leave even those who
agree intellectually our results with a painful feeling of strange-
ness: how could it explained that so many men in ail ages and
nations, among thoni eminent minds, spent so much energ}', nay
veritable fervor, oU metaphysics if the latter consisted of nothing
but mere words, nonsensically juxtaposed? And how could one ac-
count for the fact tb^t metaphysical books have exerted such a strong
influence on readers up to the present day, if they contained not even
errors, but nothing ut all? These doubts are justified since metaphysics
does indeed have a content; only it is not theoretical content. The
(pseudo) statements of metaphysics do not serve for the description
of states of affairs, neither existing ones (in that case they would be
true statements) nor non-existing ones (in that case they v/ould be
at least false statements). They serve for the expression 'of the gen-
eral attitude of a parson towards life (“Lebenseinstellung, Lebens-
gefiiiil”)-

Perhaps we may assume that metaphysics originated from myth-
ology^- The child is ungry at the ‘'wicked table” which hurt him.
Primitive man endeavors to conciliate the threatening demon of
earthquakes, or he v/orships the deity of the fertile rains in gratitude.
Here we confront personifications of natural phenomena, which are
the quasi-poetic cf man’s emotional relationship to his

environment. The heritage of mythology is bequeathed on the one
hand to poetry, whiob produces and intensifies the effects of myth-
ology on life in a dcli^oidtc way; on the other hand, it is handed down
to theology, which develops mythology into a system. Which, now,
is the historical role metaphysics? Perhaps we may regard it as a
substitute for theology systematic, conceptual think-

ing. The (supposedly) transcendent sources of knowledge of theol-
ogy axe here replaoed by natural, yet supposedly trans-empirical

[ 79 ]

_ inspection the same content as that

of iii34liology is here still recognizable behind the repeatedl}^ varied
dreeing: we find that metaphysics also arises from the need to give
expression to a man’s attitude in life, his emotional and volitional
reaction to the environment, to society, to the tasks to which he
devotes himself, to the misfortunes that befall him. TMs attitude
mamfests itself, unconsciously as a rule, in everything a man does
or says. It also impresses itself on his facial features, perhaps even
on the character of his gait. Many people, now, feel a desire to
create over and above these manifestations a special expression of
their attitude, through which it might become visible in a more suc-
cinct and penetrating way. If they have artistic talent they are'- able
to express themselves by producing a work of art. Many writers
have already clarified the way in which the basic attitude is mani-
fested through the style and manner of a work of art (e.g. Dilthey
and his students). [In this connection the term “world view*’ (‘“Welt-
anschauung”) is often used; we prefer to avoid it because of its
ambiguity, which blurs the difference between attitude and theory,
a difference which is of decisive importance for our analysis.] What
is here essential for our considerations is only the fact that art is an
adequate, metaphysics an inadequate means for the expression of ti>e
basic attitude. Of course, there need be no intrinsic objection to one’s
using any means of expression one likes. But in the case of meta-
physics we find this situation: through the form of its works it pre-
tends to be something that it is not. Ttie form in question is that
of a system of statements which are apparently related as premisCvS
and conclusions, that is, the form of a theory^ In this way the fiction
of theoretical content is generated, w'hereas, as we have seen, there
is no such content. It is not only the reader, but the metaphysician
himself who suffers from the illusion that the metaphysical state-
ments say something, describe states of affairs. The metaphysician
believes that he travels in territory^ in which truth and falsehood are
at stake. In reality, however, he has not asserted anything, but only
expressed something, like an artist. That the metaphysician is thus
deluding himself cannot be inferred from the fact that he selects
language as the medium of expression and declarative sentences as
the form of expression; for lyrical poets do the same without suc-
cumbing to self-delusion. But the metaphysician supports his state-
ments by arguments, he claims assent to their content, he polenncizes
against metaphysicians of divergent persuasion by attempting to
refute their assertions in his treatise. Lyrical poets, on the other hand,
do not try to refute in their poem the statements in a poem by some

fhk EUminatian of Metaphysics
. ' cjrtiirces of knowledge. On closer

j- gQ ] RU!X)LF CARNAP

Other lyrical poet; for they know they are in the domain of art and
not in the domain of theory.

Perhaps music is the purest means of expression of the basic
attitude because it is entirely free from any reference to objects. The
harmonious feeling or attitude, which the metaphysician tries to ex-
press in a monistic system, is more clearly expressed in the music
of Mozart. And when a metaphysician gives verbal expression to
his dualistic-heroic attitude towards life in a dualistic system, is it not
perhaps because he lacks the ability of a Beethoven to express this
attitude in an adequate medium? Metaphysicians are musicians with-
out musical ability. Instead they have a strong inclination to work
within the medium of the theoretical, to connect concepts and
thouglits. Now, instead of activating, on the one hand, this inclina-
tion in the domain of science, and satisfying, on the other hand, the
nec^d for expression in art, the metaphysician confuses the two and
produces a structure which achieves nothing for knowledge and some-
thing inadequate for the expression of attitude.

Our conjecture that metaphysics is a substitute, albeit an inade-
quate one, for art, seems to be further confirmed by the fact that
the metaphysician who perhaps had artistic talent to the highest
degree, viz. Nietzsche, almost entirely avoided the errpr of that con-
fusion. A large part of his work has predominantly empirical con-
tent. We find there, for instance, historical analyses of specific artistic
p>henomena, or an historical-psychological analysis of morals. In the
work, however, in which he expresses most strongly that which others
express through metaphysics or ethics, in Thus Spake Zarathustra,
he does not choose the misleading tlieoretical form, but openly the
form of art, of poetr>^

REMARKS BY THE AUTHOR (1957)

To section 7, ^'metaphysics/' This term is used in this paper, as
usually in Europe, for the field of alleged knowledge of the essence of
tilings which transcends the realm of empirically founded, inductive
science. Metaphysics in this sense includes systems like those of Fichte,
Schelling, Hegel, Bergson, Heidegger. But it does not include endeavors
towards a synthesis and generalization of the results of the various
sciences.

To section 1, ''meaning/' Today we distinguish various kinds of
rfieaning, in particular cognitive (designative, referential) meaning on
ttie one hand, and non-cognitive (expressive) meaning components,
e-g. emotive and motivative, on the other. In the present paper, the word

loll

Jhe Elimination of Metaphysics i ■*

“meaning” is always understood in the sense of “co^itive meanmg.”
The thesis that the sentences of metaphysics are meanmgless,
he understood in the sense that they have no cognitive meaning, no asser-
tive content. The obvious psychological fact that they have expressi
Lanin- is thereby not denied; this is explicitly stated m Section 7.

6, “metalogicr This term refers to the theoir of ex^«-
cions of a language and, in particular, of their logical relations. Tod y
we would distinguish between logical syntax as the theory of y
formal relations and semantics as the theory of meaning and truth-

contoons.^^^ 6, realism and idealism. That both the affirmative and ffie
negative theses concerning the reality of the external world are pseudo-
Ltements, I have tried to show in the monograph Schemprobleme m
der Philosophic: Das Fremdpsrychische and der Reahsmusstreit, BeiUn.
1928 The similar nature of the ontological theses about the reality or
unreality of abstract entities, e.g., properties, relations propositions, is
discussed in “Empiricism, .Semantics, and Ontology, Revue
Philos. 4, 1950, 20-40, reprinted in: Meaning and Necessity, secona edi-

tion, Chicago, 1956.

4

Positivism and Realism
BY MORITZ SCHLICK
(translated by DAVID RYNIN)

1. Preliminary Questions

Every philosophical poimt of view is defined by the principles
which it considers fundamental and to which it constantly recurs in
argument. But in the course of the historical development of such a
view these principles tend to change — whether they be reformulated,
extended, or restricted, or even gradually altered in meaning- At
some time then the question arises whether we should still speak of
the development of the one point of view at all, and retain its old
name; or whether a new viewpoint has arisen.

If, along with the developed view there also exists an “orthodox”
viewpoint which retains the first principles in their original form and
meaning, sooner or later some terminological distinction between tlie
old and the new will arise automatically. But where tliis is not clearly
the case, where rather the different exponents of a “viewpoint” em-
ploy extremely different, even contradictory, formulations and mean-
ings of the principles, confusion arises; the adherents and opponents
of the view talk at cross purposes; each selects those statements
which can be used in defense of his own opinions, and all ends in fatal
misunderstanding and obscurity. These confusions disappear only
when the different principles are distinguished, and each is tested sep-
arately for its meaning and truth. In such an examination of prin-
ciples one quite ignores, for the time, the question of the historical
contexts of their origins, and of their names.

I should like to apply these considerations to the modes of think-

Tiiis article first appeared in Erkenntnis, Volume III (1932/33) and is here re-
published with the kind permission of Mrs. SchHck and Professor Carnap. It was
written in response to criticisms of positivism in a lecture by Max Planck entitled
“Positivismus und Reaie Aussenwelt,” published in 1931 by the Akademische Ver-
lagsgeseilschaft, Leipzig.

C 82 ]

■vl */'.'' ' Positivism and Realism [ ]

^ ' iBg grouped together under the name “positivism.” They have, from
the time August Comte invented the term until the present, under-
gone a development which furnishes a good example of what has
just been said. But I do not do this with the historical aim, say, of
determining a strict concept of positivism as it has appeared in his-
tory, but rather in order to contribute something to a positive settle-
ment of the dispute carried on nowadays concerning certain prin-
ciples which pass as fundamental to positivism. Such a settlement
concerns me the more because I myself advocate some of these
principles. I am concerned here only to make their meaning as clear
as possible; whether or not one will, after this clarification, attribute
tliem to “positivism’'* is a question of very little importance.

If one wishes to characterize every view which denies the possi-
bility of metaphysics as positivistic this is quite unobjectionable, as
a mere definition; and I should in this sense call myself a strict
positivist. But this holds, of course, only under the presupposition
of a special definition of “metaphysics.” WTiat the definition of meta-
physics is which must be adopted here need not interest us at the
moment; but it hardly agrees with the formulations usual in philo-
sophic literature, and further determinations of positivism which
refer to such formulations lead at once into confusions and difficulties.

If we say, as frequently has been said, that metaphysics is the the-
ory^ of “trae being,” of “reality in itself.” of “transcendent being” this
obviously implies a (contradictory) spurious, lesser, apparent being;
as has indeed been assumed by all metaphysicians since the time of
Plato and the Elcatics, This apparent being is the realm of “appear-
ances,” and while the true transcendent reality is to be reached only
with difficulty, by the efforts of the metaphysician, the special
sciences have to do exclusively with appearances w'hich are perfectly
accessible to them. The difference between the ways in wliich these
two “modes of being” are to be known, is then explained by the
fact that the appearances are immediately present, “given,” to us,
while metaphysical reality must be inferred from them in some
roundabout manner. And thus we seem to arrive at a fundamental
concept of the positivists, for they always speak of the “given,” and
usually formulate their fundamental principle in the proposition that
the philosopher as well as the scientist must always remain within
the given, that to go beyond it, as the metaphysician attempts, is
impossible or senseless.

Thus it amounts to identifying the “given” of the positivist with
the “appearances” of metaphysics, and to believing that positivism
is at l^ttom a metaphysics, from which one has left, or stricken,

[ 84 I MORITZ SCHLICK

out the transcendent; and such an opinion may indeed often enough
have inspired the arguments of the positivists, as well as those of
their opponents. But this belief finds us well on our way to dangerous
errors.

The term “the given” itself is a cause of grave misunderstandings,
“To give” usually connotes a three term relation: it presupposes
first, someone who gives, secondly, one to whom is given, and thirdly,
something given. The metaphysician finds this quite in order, for
what gives is the transcendent reality, what receives is the knowing
mind, which makes what is given to it into its “content.” But evi-
dently the positivist will from the very outset have nothing to do
with such notions; the given is for him but a word for what is most
simple and no longer questionable. No matter what word we choose,
every one will be capable of misinterpretations; if we speak of
“experiences” we seem to presuppose the distinction between what
experiences and what is experienced; with the use of the phrase “con-
tent of consciousness” we seem burdened with a similar distinction,
and in addition with the complicated concept of “consciousness,”
which in any case did not exist until invented by philosophy.

But even apart from such difficulties it is perhaps stiU not clear
what is actually meant by the given. Do only such “qualities” as
“blue,” “warm,” “pain,” come under this heading, or e.g. also
relations between them, or their order? Is the similarity of two
qualities “given” in the same sense as the qualities themselves? And
if the given is somehow worked up or interpreted or judged is
this working-up or judging not also in some sense something given?

But it is not obscurities of this sort that give rise to the current
matter of dispute: the bone of contention appears among the various
parties only with the question of “reality.”

If the rejection of metaphysics by positivism signifies the denial
of transcendent reality then it seems the most natural conclusion in
the world that the positivist attributes reality only to non-transcendent
being. The fundamental principle of the positivist then seems to run:
“Only the given is real.” If one enjoys word-play one can lend to
this proposition the semblance of tautological self-evidence by
making use of a peculiarity of the German language in thus formu-
lating it: “Es gibt nur das Gegebene.” (There is only the given.)

What shall we make of this proposition? Many positivists may
have expressed and advocated it (especially, perhaps, those who
represented physical objects as “mere logical constructions,” or
“mere auxiliary concepts”), while this view has been attributed to
others by their opponents. We must insist, however, that whoever

Positivism and Realism [ ]

States this proposition seeks to establish an assertion which is
metaphysical in exactly the same sense and degree as its apparent
contradictory: “There is a transcendent reality.”

The problem about which the matter revolves here is evidently
the so-called problem of the reality of the external world, and there
seem to be two parties: that of “realism” which believes in the
reality of the external world, and that of “positivism” which does
not. In truth, I am convinced that it is quite senseless to set two
views in opposition in this manner, for neither party really knows
what it wants to say (which is the case v/ith every metaphysical
proposition.) But before I explain this I should like to show how
the more obvious interpretations of the proposition “only the given
is real” actually lead at once to well-known metaphysical views.

This problem can take the form of the question about the existence
of the “external” world only if somehow we can distinguish between
inner and outer; and this distinction is made by considering the
given as a “content” of consciousness, as belonging to one or several
subjects to whom it is given. Thus the immediate datum would have
attributed to it some sort of mental character, the character of a
representation or an idea; and the proposition would then state that
this character pertained to all reality: no being outside of conscious-
ness. But this is nothing but the fundamental principle of metaphysical
idealism. If the philosopher thinks himself able to speak only of
what is given to himself we have before us a solipsistic metaphysics,
but if he thinks he may assume that the given is distributed among
many subjects we have a metaphysics of the Berkeleyan variety.

On this inteipretation fX)sitivism would be simply identical wnth
the older idealistic metaphysics. But since its founders certainly
desired something quite ditTerent from a renewal of that idealism,
this interpretation is to be rejected as contrary to the anti-metaphysicai
attitude of positivism. Idealism and positivism are incompatible.
The positivist Ernst Laas has written a work of several volumes to
demonstrate the irreconcilable opposition which exists on all points
between them; and if his student Hans Vaihinger gave to his “Philos-
ophy of As If” the subtitle an “idealistic positivism” it is but one of
the contradictions from which this work suffers. Ernst Mach es-
pecially emphasized that his own positivism developed in an opposite
direction to that of Berkeleyan metaphysics; and he and Avenarius
laid great stress upon not taking the given as a content of conscious-
ness. They tried to exclude this concept from their philosophy
altogether.

In view of the uncertainty in the camp of the positivists them-

[ 86 ] MORITZ SCHLICK

selves it is no wonder that the “realist” fails to observe the distinctions
we have discussed, and directs his arguments against the thesis:
“There is nothing but the contents of consciousness,” or “There is only
an internal world.” But this proposition belongs to idealistic meta-
physics, and has no place in an anti-metaphysical positivism, which is
not affected by these realistic arguments.

Of course the realist can think that it is simply inevitable to
conceive the given as contents of consciousness, as subjective, as
mental — or whatever expression is used; and he will then consider
as a failure the attempt of Mach and Avenarius to take the given
as neutral and to resolve the distinction between inner and outer,
and will believe that a view free of any metaphysical basis is im-
possible. But this line of thought is rarely met with. And however
it may fare, in any case, the whole business is much ado about
nothing, for the “problem of the reality of the external world” is a
meaningless pseudo-problem. This must now be made evident.

2. On the Meaning of Propositions

It is the peculiar business of philosophy to ascertain and make
clear the meaning of statements and questions. The chaotic state
in which philosophy has found itself during the greater part of its
history is due to the unfortunate fact that, in the first place, it took
certain formulations to be real questions before carefully ascertaining
whether they really made any sense, and, in the ''second place, it
believed that the answers to the questions could be found by the aid
of special philosophical methods, different from those of the special
sciences. But we cannot by philosophical analysis decide whether
anything is real, but only what it means to say that it is real; and
whether this is then the case or not can be decided only by the usual
methods of daily life and of science, that is, through experience. Hence
we have here the task of making clear to ourselves whether any mean-
ing can be attached to the problem of the reality of the “external
world.”

When, in general, are we sure that the meaning of a question is
clear to us? Evidently when and only when we are able to state
exactly the conditions under which it is to be answered in the
aSirmative, or, as the case may be, the conditions under which it is
to be answered in the negative. By stating these conditions, and by
this alone, is the meaning of a question defined.

It is the first step of any philosophizing, and the foundation of
all reflection, to see that it is simply impossible to give the meaning
of any statement except by describing the fact which must exist if

.'p^ and Realism ' [ H7 ]

' 'the statement is to be true. If it does not exist then the statement is
” ■ false. The meaning of a proposition consists, obviously, in this

; alone, that it expresses a definite state of affairs. And this state of
'' ' ■ affairs must be pointed out in order to give the meaning of the
proposition. One can, of course, say that the proposition itself
already gives this state of affairs. This is true, but the proposition
indicates the state of affairs only to the person who understands it.
But when do I understand a proposition? When I understand the
meanings of the words which occur in it? These can be explained
by definitions. But in the definitions new words appear whose meanings
cannot again be described in propositions, they must be indicated
directly: the meaning of a word must in the end be shown, it must be
given. This is done by an act of indication, of pointing; and what
is pointed at must be given, otherwise I cannot be referred to it.

Accordingly, in order to find the meaning of a proposition, we
must transform it by successive definitions until finally only such
words occur in it as can no longer be defined, but whose meanings
can only be directly pointed out. The criterion of the truth or falsity
of the proposition then lies in the fact that under definite conditions
(given in the definition) certain data are present, or not present.
If this is determined then everything asserted by the proposition is
determined, and I know its meaning. If I am unable, in principle,
to verify a proposition, that is, if I am absolutely ignorant of how to
proceed, of what I must do in order to ascertain its truth or falsity,
then obviously I do not know what the proposition actually states,
and I should then be unable to interpret the proposition by passing
from the words, with the aid of the definitions, to possible experiences.
For in so far as I am able to do this I am also able in the same way to
state at least in principle the method of verification (even though,
often, because of practical difficulties I am unable to carry it out) . The
statement of the conditions under which a proposition is true is
the same as the statement of its meaning, and not something different.

And these conditions,'' we have already seen, must finally be
discoverable in the given. Different conditions mean differences in
the given. The meaning of every proposition is finally to be determined
by the given, and by nothing else.

I do not know if this insight ought to be called positivistic; but
of course I should like to believe that it underlay ffil those efforts
which appear by this name in the history of philosophy, whether or
not it was ever clearly formulated. We may indeed assume that it
constitutes the real nucleus and motive force of many quite perverted
formulations which we find among positivists.

[ 88 ] MORITZ SCHLICK

If we but once attain the insight that the meaning of every prop-
osition can be determined only by means of the given we can no
longer conceive the possibility of another opinion, for we see that
we have discovered simply the conditions under which opinions in
general can be formulated. Hence it would be quite mistaken to see,
somehow, in what we have said a “theory of meaning” (in Anglo-
Saxon countries this insight, that the meaning of a proposition is
determined wholly and alone by its verification in the given, is often
called the “experimental theor}^ of meaning”). What precedes every
formulation of a theory cannot itself be a theory.

The content of our insight is indeed quite simple (and this is the
reason why it is so sensible). It says: a proposition has a statable
meaning only if it makes a verifiable difference whether it is true or
false. A proposition which is such that the world remains the same
whether it be true or false simply says nothing about the world; it is
empty and communicates nothing; I can give it no meaning. We have a
verifiable difference, however, only when it is a difference in the
given, for verifiable certainly means nothing but “capable of being
exhibited in the given.”

it is obvious that verifiabiiitx^ is used here in the sense of “verifi-
able in principle,” for the meaning of a proposition is, of coarse,
independent of whether the conditions under which we find ourselves
at a specified time allow or prevent the actual verificadon. There is
not the least doubt that the proposition “there is a mountain of a
height of 3000 meters on the other side of the moon” makes good
sense, even though we lack the technical means of verifying it. And
it would remain just as meaningful if one knew with certainty, on
scientific grounds, that no man would ever reach the other side of
the moon. The verification remains conceivable; we are always able
to state what data we should have to experience in order to decide
the truth or falsity of the proposition; the verification is logically
possible, whatever be the case regarding its practical feasibility,
and this alone concerns us.

But if someone should say: within every electron there is a
nucleus, which, though always present, never has in any way any
external effects, so that its existence never manifests itself in nature —
this would be a meaningless assertion. For we should have to ask
the maker of the hypothesis: what do you really mean by the presence
of that “nucleus”?; and he could answer only: I mean that something
exists there in the electron. We should inquire further: what does
that mean? What would be the case if it didn’t exist? And he would
have to answer: everything would remain exactly the same as before.

r'- positivi^^ and Realism [ j

\ P0|. according to his assertion, the “somewhat” in the electron has

' 20 effects, and there would simply be no observable change: the

/ lealin of the given would not be affected in any way. We should
judge that he had not succeeded in communicating the meaning of
his hypothesis, and that therefore it made no sense. In this case the
: impossibility of verification is not factual, but logical, for by reason
of the utter ineffectiveness of that nucleus a decision regarding it
based on differences in the given is in principle excluded.

One cannot here suppose that the distinction between the im-
possibility of verifying something in principle and the mere factual,
empirical impossibility is not clear, and is therefore sometimes
difficult to draw; for the impossibility in principle is logical impos-

sibility which does not differ in degree from empirical impossibility,
but in very essence. What is empirically impossible still remains
conceivable, but what is logically impossible is contradictory, and
cannot therefore be thought at all As a matter of fact we find that in
scientific thinking this distinction is always clearly and instinctively
felt. The physicists were the first to reject the statement given in our
example regarding the forever hidden nucleus of the electron, with
the criticism that it was no hypothesis at all, but mere empty word
play. And in all times the most successful scientific investigators
have adopted this standpoint with respect to the meaning of their
statements, since they have acted in accordance with it, even if for the
most part unconsciously.

For science, then, our standpoint does not represent something
foreign and out of the ordinary, but it has in a certain sense always
been more or less taken for granted. It could not be othei-wise, because
only from this standpoint is a proposition verifiable at all; and since
all the activities of science consist in examining the truth of propo-
sitions, it continuously acknowledges the correctness of our insight
by its practice.

If express confirmation were still necessary^ it would be found
most conspicuously at critical points in the development of sci-
ence where investigation is forced to bring the self-evident pre-
suppositions to light. This is the case where difficulties of principle
lead one to suppose that something may be wrong with these pre-
suppositions. The most famous example of this sort, which will
remain forever memorable, is Einstein’s analysis of the concept of
time, which consists in nothing but the analysis of the meaning of our
statements about the simultaneity of spatially separate events.
Einstein said to the physicists (and to the philosophers): you must
first state what you mean by simultaneity, and you can do this only

* '4' -It’.-’

t ] MORITZ SCHLICK

by showing how the proposition “two events are simultaneous” is
verified. But with this you have completely determined its meaning.
What is true of the concept of simultaneity holds of every other
concept: every proposition has meaning only in so far as it can be
verified, and it says only what is verified, and simply nothing more.
If one should say that it did contain something more he must be able
to say what more this is, and to do this he would have to tell us how
the world would differ if he were mistaken. But this cannot be done,
since by assumption all the observable differences are already in-
cluded in the verification.

In the example of simultaneity the analysis of the meaning, as is
appropriate for the physicist, is carried only to the point where the de-
cision regarding the truth or falsity of a proposition about time is based
on the occurrence or non-occurrence of a definite physical event (e.g.
the coincidence of a pointer with a point on a scale). But it is clear
that one can ask further: what does it mean to say that the pointer
indicates a definite point on the scale? And the answer can only be
made by reference to the occurrence of certain data, or as one gen-
erally says, certain ‘^‘sense-impressions.’* This will be generally ad-
mitted, especially by physicists. “For positivism will always be right
in this, that there is no other source of knowledge than sense-impres-
sions says Planck^ and this evidently means that the truth or
falsity of a physical statement depends entirely upon the occurrence
of certain sense-impressions (which constitute a soecia! class of data).

But there will always be many who are inclined to sav: granted
that the truth of a physical statement can be tested only bv the occur-
rence of certain sense-impressions, this is not the same as asserting
that the meaning of the statement is also therebv exhaustively sjiven.
This latter must be denied: a proposition can contain more than can
be verified; that the pointer stands at a definite point on the scale
means more than the existence of certain sensations (namely “the
existence of a definite fact in the external world”).

In answer to this denial of the identity of meaning and verifica-
tion we must point out the following: 1) This denial is found among
physicists only when they leave the actual sphere of physical state-
ments and begin to philosophize. (In physics, obviously, there occur
only statements about the properties or behavior of things or events,
an express statement concerning their “reality” is not" a scientific
statement but a philosophical one). In his own sphere the physicist
adinits entirely the correctness of our standpoint. We mentioned this
earlier, and illustrated it in the example of simultaneity. There are

1. Positivismus und Reale Aussenwelt, p. 14.

and Realism [ ]

indeed many philosophers who say: of course we can determine only
illative simultaneity, but it does not follow from this that there is
I 00 such thing as absolute simultaneity, and we continue to believe
in it! The falsity of this statement cannot in any sense be demon-
- strated, but the overwhelming majority of physicists is rightly of the
I opinion that it is meaningless. However it must be sharply empha-
I sized that in both cases we have to do with the same situation. There
I is in principle no difference whether I ask: does the proposition “two
; events are simultaneous” mean more than can be verified? Or whether
I ask: does the proposition “the pointer points toward the fifth line
on the scale” mean more than can be verified? The physicist who
; handles these two cases differently is guilty of an inconsistency. He
will of course justify himself, believing that in the second case where
; the question concerns the “reality of the external world” much more
; is at stake, philosophically. Tliis argument is too vague for us to
attach much weight to it, but we shall see presently whether anything
lies behind it.

2 ) It is perfectly true that every statement about a physical
object or an event means more than is verified, say, by the occurrence
■ of a single experience. It is rather presupposed that the experience
occurred under very^ definite conditions, whose realization of course
can only be verified by something given, and it is presupposed farther
that ever more verifications are possible (confirmations etc.), which
in their turn, naturally, reduce to certain given events. In this manner
one can and must give an account of illusions of sense, and of error,
and it is easy to see how those cases are to be included in which we
should say the observer was merely dreaming, that the pointer in-
dicated a definite line, or that he did not carefully observe, etc. The
assertions of Blondlot about N-Rays which he believed himself to
have discovered were certainly more than statements that under
certain conditions he had experienced certain visual sensations; and
because of this, of course, they could be refuted.- Strictly speaking,
the meaning of a proposition about physical objects would be ex-
hausted only by an indefinitely large number of possible verifications,
and we gather from this that such a proposition can in the last
analysis never be shown to be absolutely true. It is indeed generally
recognized that even the most certain propositions of science are
always to be taken as hypotheses, which remain open to further
refinement and improvement. This has certain consequences for the
logical nature of such propositions, but these do not interest us here.

Once again: the meaning of a physical statement is never de-

2. Cf. Planck, op. cit., p. 11.

[ 92 ] MORITZ SCHLICK

termined by a single isolated verification, but it must be thought of
in the fom: If conditions x are given, the data y occur, where we
can substitute an indefinitely large number of conditions for x, the
proposition remaining true for each case. (This holds even when the
statement refers to a single happening — a historical event, for such
an event has innumerable consequences whose occurrences are veri-
fiable). Thus the meaning of every physical statement is lodged finally
in an endless concatenation of data; the isolated datum therefore is
here uninteresting. Hence if any positivist ever said that the only
objects of science are the given experiences themselves he was
certainly quite mistaken; what alone the scientists seek are the rules
which govern the connections among experiences, and by means of
which they can be predicted. No one will deny that the sole verifica-
tion of natural laws lies in the fact that they yield such true predic-
tions. The common objection that the immediately given, which at
most can be but the object of psycholog}% is thus falsely made into
the object of physics is in this way refuted.

3) Most important however: if anyone is of the opinion that
the meaning of a proposition is nevertheless not exhausted by what
can be verified in the given, but extends far beyond it, he must at
least admit that this additional meaning cannot in any way be
described, stated, or expressed in language. For let him tiy^ to com-
municate this additional meaning! To the extent toAvhich he -succeeds
in communicating something about this additional meaning he will
find that the communication consists in the fact that he has indicated
certain conditions which can serve for verification in the given, and
thus he finds our position confirmed. Or else he believes himself to
have given a meaning, but closer examination shows that his words
express only that something more is there, concerning whose nature
simply nothing is said. And then in fact he has communicated nothing,
and his assertion is meaningless. For one cannot assert the existence
of something without saying what one asserts to exist. This is ob-
vious in the case of our example of the “nucleus of the electron" which
in principle lies beyond experience; yet for clarity's sake we shall con-
sider another example which brings out an important point of prin-
ciple.

I observe two pieces of green paper and determine that they
have the same color. The proposition which asserts the sameness
of color is verified, among other ways, by the fact that at the same
time I have two experiences of the same color. The proposition:
■“there are two spots of the same color before me now” cannot be
reduced to any others; it is verified by the fact that it describes the

tipasltivism and Realism [ ]

: riven. It has a dear meaning: by virtue of the meanings of the
words involved in the proposition, it signifies just the existence of color
sameness; and by virtue of linguistic usage the proposition expresses
just that experience. Now I show one of these two pieces of paper
to a second observer, and ask the question: does he see the green
as I do? Is his color experience like my color experience? This case
differs in principle from that just considered. While there the state-
ment was verifiable by the experience of color sameness, here, brief
reflection shows, such a verification is simply impossible. Of course
the second observer, if he is not color blind, calls the paper green,
and if I describe this green to him more closely by saying: it is
yellower than this carpet, but bluer than the billiard cloth, darker
than this plant, etc., he will find the same to hold in his experience,
i.e. he will agree with my statements. But even if all his judgments
about color agree entirely with mine I cannot infer from this that he
experiences this same quality. It could be the case that on looking
at the green paper he would have a color experience which I would
call '‘red,” that on the other hand, when I see red he would see green,
calling it “red” of course, and so on. Indeed it might even be that
my color sensations correspond to his tone experiences, or to any
other data. It would nevertheless forever be impossible to discover
these differences, between his and my experience. We should always
understand one another perfectly, and could never be of different
opinions regarding our environment if (and this is the only assumption
that need be made) the inner order of his experiences agreed with
that of mine. There is no question here of their “quality,” all that is
required is that they can be arranged into systems in the same manner.

All this is indeed admitted, and philosophers have often pointed
it out. But, for the most part, while they have allowed that such sub-
jective differences are theoretically possible, and that this possibility
raises a very interesting question of principle, they have held it to be
“highly probable” that the other observer and I do in fact have the
same experience. But, we must point out, the statement that different
individuals have the same experience has its sole verifiable meaning in
the fact that all their assertions (and of course all the rest of their
behavior) exhibit certain agreements. Hence it follows that the state-
ment means nothing but this. It is only to express the same thing in a
different manner if we say that we here are concerned with the simi-
larity of two system-orders. The proposition that two experiences of
different subjects not only occupy the same place in the order of a sys-
tem but are, in addition, qualitatively similar has no meaning for us.
Note well, it is not false, but meaningless: we have no idea what it

[ 94 ] MORITZ SCHLICK

Experience shows, however, that most people find it ver>^ difficult
to agree to this. We must make it clear that here we have to do with a
logical impossibility of verification. It makes good sense to speak of
the similarity of data in the same consciousness, for it can be verified
through an immediate experience. But if we want to speak of the
similarity of data in different consciousnesses we are dealing with a
new concept, which has to be newly defined. For the statements in
which it occurs are no longer verifiable in tlie old manner. The new
definition is simply the similarity of all relevant reactions of the two
individuals; we can find no other. Most people, of course, believe
that no definition is required here; one knows the meaning of
“similar” without it, and the meaning in both cases is the same. But,
to recognize this as a mistake we need only remember the concept
of simultaneity, in which the situation is exactly the same. To the
concept of “simultaneity at a place” there corresponds the concept
of “similarity of the experiences of the same individual,” and to
“simultaneity at different places” there corresponds the notion of
“similarity of the experiences of different persons.” The second
notion is, with respect to the first, a new concept in each case, and
must be specially defined. We can no more indicate a directly ex-
periencable quality which would verify the similarity of two greens
in different consciousnesses than we can for simultaneity at different
points: both must be determined by a system of relations.

Many philosophers have sought to overcome the difficulty which
seemed to confront them here by all sorts of speculations and ideal
experiments, speaking, say, of a universal consciousness comprehend-
ing all individuals (God) or thinking perhaps that by means of some
artificial connection of the nervous systems of two individuals the
sensations of one would be made accessible to the other, and thus
be rendered comparable. But of course all this is in vain. For even
in this fantastic way in the end only the contents of one and the same
consciousness would be directly compared. The question, however,
concerns the possibility of the comparison of qualities in so far as
they belong to different, and not the same, consciousnesses.

Hence it must be granted that a statement concerning the simi-
larity of the experiences of two persons has no other communicable
meaning than a certain agreement of their reactions. Of course
everyone is free to believe that such a proposition also possesses
another more direct meaning; but so much is sure: no such meaning
is verifiable, and one cannot in any way state or show what this
meaning is. Hence it follows that such a meaning simply cannot
in any way become the object of discussion. We can say absolutely

, : [95]

^ Positivism and Realism

about it, and it can in no way enter into any J

means°of which we communicate with one another. And ^ ^ ’

fS become clear here holds generally. We can understand n a
oroposition only what it communicates, and a meaning . ,

SSy if it is verifiable. Since propositions are

for conuBunication we can include in their meanings ^ny ^ Y

S.“ «icate. For fitis reason I shonld maintain that “nreamng

ran mean only “verifiable meaning.”

But even if someone should insist that there is a non-veri
meaning this would not help in the least. For such a meamng can
S no way enter into anything he says or asks, or into what we aA
him or answer him. In other words; if there were any such thi p,

S our utterances, arguments, and modes of f

Quite unaffected bv it, whether we were dealing with daily life, ethical
TaBthSc attitudes, with science or philosophy. Ever^hmg wouU
remain as if there were no unverifiable meamng. For if there were
a difference this very difference would make it verifiable.

This is a serious situation, and we must insist that it be taken
seriouslv. Above all one must guard against confusing this lo^^
impossibility with an empirical incapacity, as if some technical
culty and human imperfection were responsible for the fact that oriy
what is verifiable can be expressed, and as if there were still some rcc
entrance throuah which an unverifiable meaning might sip m ami
make itself evident in our discourse and behavior. No. The tn^OTi-
municability is absolute; he who believes (or

he believes) in a non-verifiable meaning must nevertheless admit u c
with respect to it only one course is open to him: utter silence.
Neither he nor we gain anything, no matter how often he a^rts y
there is a non-verifiable meaning!” For this statement itself is devoid
of meaning, it tells us nothing.

3. WH.'tT IS THE Meaning of “Reality,”

OF “External World”?

We are now prepared to apply what has been said to the so-called
problem of the reality of the external world. ^

We ask: What is the meaning of the realist’s assertion, there
is an external world?” or what is the meaning of the statement
(attributed to the positivist by the realist) “there is no external
world”?

In order to answer the question it is of course necessary to make
clear the meanings of the words, “there is,” and pxtemal world.
We begin with the first. “There is an x” means the same as x is

[ 96 ] MORITZ SCHLICK

real” or “x is actual.” Hence what do we mean when we attribute
reality to an object? It is an old, very important logical or philosophi-
cal insight, that the proposition “x is real” is of quite a different sort
from a proposition which ascribes some property to x (e.g. '‘x is
hard.”) In other words: reality or existence is not a predicate. The
statement “the dollar in my pocket is round” has a completely
different logical form from that of the statement “the dollar in my
pocket is real.” In modern logic this distinction is expressed by
means of two very different symbolisms, but it was already clearly
drawn by Kant, who, as we know, in his critique of the so-caUed
ontological proof of God’s existence, correctly found the source of
error of this proof in the fact that existence is treated as a predicate.

In daily life we constantly speak of reality or existence, and for
this reason it cannot be very difficult to discover its meaning. In a
law-suit it is often necessary to determine whether a certain docu-
ment actually exists, or whether it is merely wrongly asserted to
exist; and it is not altogether unimportant to me whether the dollar
in my pocket is only imagined or is real. Now everyone knows how
such an assertion of the reality of something is verified, and there
cannot be the slightest doubt that the reality of the dollar is verified
and verified only by the fact that, as a result of certain suitable
manipulations, I obtain certain sensations of touch and sight upon
w'hose presence I am accustomed to say “this is a dollar.” The same
holds of the document, except that in this case we would content
ourselves with certain statements of others who claim to have seen
the document, i.e. to have had perceptions of a veiy^ definite sort.
And the “statements of others” consist again of certain acoustic, or,
if they were WTitien statements, of certain visual perceptions. No
special analysis is required of the fact that the occurrence of certain
sense-perceptions among the data always constitutes the sole criterion
of statements concerning the reality of a “physical” object or event in
everyday life, as well as in the most subtle propositions of science.
That there are okapis in Africa can be determined only by the
fact that such animals are observed there. However it is not necessary
that the object or event “itself” be perceived. We can, for example,
imagine the existence of a transneptunian planet to be inferred with
as much certainty from the observation of perturbations as from the
direct perception of a spot of light in the telescope. The reality of
atoms furnishes us with another example. And the same is true of the
other side of the moon.

It is of great importance to realize that the occurrence of a
definite single experience in the verification of a proposition about

. Positivism and Realism [ I

'nature is: often not accepted as verifying the proposition, but that
throughout we are concerned with uniformities, with^ connectioiis
obeying natural laws: in this manner genuine verifications are dis-
tinguished from illusions and hallucinations. When we say of any
object or event — ^which must be designated by a description — ^that
it is real this means that there exists a very definite connection
between perceptions or other experiences, that under certain condi-
tions certain data appear. Such a statement is verified in this manner
.alone, and therefore it has only this communicable meaning.

This was in principle already formulated by Kant, whom no
one would charge with ‘"positivism.” Reality for him is a category,
and if w^e apply it in any way, and say of an object that it is real this
means, according to Kant, that it belongs to a collection of percep-
tions connected according to some natural law.

We see that for us (as for Kant; and the same applies to every
philosopher who understands his business) it is simply a matter of
saying what it means in eveiyday life or in science to ascribe real
existence to a thing. Our task is in no sense that of correcting the
statements of everyday life or of science. 1 must confess that I should
repudiate and consider absurd any philosophical system that in-
volved the assertion that clouds and stars, mountains and sea were
unreal, that the chair by the wall ceased to exist whenever I turned my
back. Nor do I credit any serious thinker with any such statement.
It w^ould for example surely be quite a perverse interpretation of
Berkeley's philosophy to see in it such a system. He too didn’t deny
the reality of the world of bodies, but merely tried to explain what
we mean when we ascribe reality to it. He who says that unperceived
ideas exist in God’s mind does not thereby deny their existence but
seeks to understand it. John Stuart Mill himself did not wish to deny
the reality of physical bodies, but to clarify it, when he declared
them to be "'permanent possibilities of sensation,” though in my
opinion his manner of expression was veiy ill chosen.

Therefore if one understands by "'positivism” a view which denies
the reality of bodies I must declare positivism to be simply absurd.
But I do not believe that such an interpretation of positivistic views
would be historically just, at least so far as their ablest representatives
are concerned. Be this as it may, w'e are not concerned v/ith it, but
with the view' itself. And in this connection we have seen that our
principle, that the meaning of a proposition is identical with its veri-
fication, leads to the insight that the assertion of the reality of a
thing is a statement regarding a regular connection of experiences.
It does not lead to the conclusion that the assertion is false. (There-

[ 98 ]

fore reality is not denied to physical things in favor of sensations.)
with expounded are not at all satisfied

Sp? following answer; “You do

indeed, admit the realty of the physical world, but, as it seems to us’
only verbally. You simply call that real which we would describe as a
mere conceptual construction. When we use the word rSfity we
mean by it something quite different from what you mean Your
definition of reality refers back to experiences; but we mea^ome-
thmg altogether independent of experience. We mean somethint^

to^the dTf?'?' "T® independence evidently attributed by you

to the data alone, m the sense that you reduce everythin^ to £
as to something not further reducible.” ^ ° ^

to ^ to invite our opponents

vcrSSf Ld propositions are verified. S? htw

coyider the psycholoS afiLrSthL'ti

“con'ttnt“S "’’"‘“r on our view a reaiity is attributed to a
content of consciousness” which is denied to a physical obiect

to hv -1‘w a datum is possible only if it"is referred

S course rC^’rJ"'’ <Jhec. indicaSof Sds

loat T * ^ ‘ ^ consciousness.” Qn the language of symbolic

s ctLs rL‘S,””sSr“-

ra;Thavt"Z“io”rfy“ "Ur

and dteSS fhe LT'asThl - hVe?"

be written in Russell’s; cumhrvr meaningless, and cannot

Descartes” stat« “-I ‘“'Sht that

Uon, -4 ?«er of conse^Se : SL» 'l! ““‘f
it expresses nothing and SS no

loTr ‘ T? i --

be tested. A proposition only has meS^is vlrmabSw'ff

Positivism and Realism [ ]

state the conditions under which it would be true and under which
it would be false. But how shall I describe the conditions under which
the proposition “my contents of consciousness exist” would be false?
Every attempt would lead to absurdity, for example to such state-
ments as “it is the case that nothing is the case,” or something of the
sort. Therefore it is self-evident that I cannot describe the conditions
which make the proposition true (try to do so!). There is indeed
also no doubt that Descartes failed to gain any knowledge through his
statement, and was no wiser at the end than he was at the beginning
of his inquiry.

No, a question concerning the reality of an experience makes
sense only if its reality can significantly be doubted. I can for ex-
ample ask: Is it really true that I felt happy upon hearing that news?
This can be verified or falsified in exactly the same way as, say, the
question: is it true that Sirius has a satellite (that this satellite
is real)? That on a given occasion I exp>erienced pleasure can for
example be verified by examining the statements of others concern-
ing my behavior at the time, by finding a letter written by me at
the time, or even simply by a veridical memoiy' of the emotion ex-
perienced. Hence there is here absolutely no difference in principle:
to be real always means to stand in a definite relationship to the
given. And this ^so holds, say. for an experience at this very moment.
For example, I can significantly ask (say in the course of a physio-
logical experiment): do I, or do I not. experience a pain, at this
moment? Observe that here “pain" does not function as a proper
name for a this-here, but represents a concep>t which stands for a
describable class of experiences. Here, too, the question is answered
by determining that an experience having certain describable prop-
erties occurs in conjunction with certain conditions (experimental
conditions, concentration of attention etc.). Such describable prop-
erties would be, for instance, similarity to an experience occurring
under certain other conditions; the tendency to produce certain reac-
tions, etc.

No matter how we twist and turn: it is impossible to interpret
an existential proposition except as a statement regarding a con-
nection of perceptions. It is reality of the same sort that one must
attribute to data of consciousness and, say. to physical events. Hardly
anything in the history of philosophy has produced greater con-
fusion than the attempt to distinguish one of the two as true “being.”
Wherever the word “real” is significantly used it means one and the
same thing.

The opponent of this view will perhaps not feel that what has

MORITZ SCHLICK

[ 100 ]

been said upsets Ms own view in any way, but will be of the impress
sioE that the preceding arguments presuppose a point of departure
he is from the outset unwilling to adopt. He must indeed grant
that a decision regarding the reality or unreality of a fact in ex-
perience is always made in the way described, but he claims that
in this way one arrives only at what Kant called empirical reality.
This method defines the realm of the observations of everyday life
and of science, but beyond this limit lies something more, the
transcendent reality, which cannot be deduced by strict logic, and
therefore is not a postulate of the understanding, but is perhaps a
postulate of reason. This is the only real external world, and it alone
is relevant to the philosophical problem of the existence of the ex-
ternal world. Thus our discussion leaves the question of the meaning
of the word “reality,” and turns to that of the phrase “external world.”

The phrase “external world” is evidently used in two different
W’'ays: first in the language of everyday life, and secondly as a tech-
nical term in philosophy.

Wherever it occurs in daily life it has, as do most of the expres-
sions used in practical affairs, a sensible meaning which can be
stated. In opposition to the “inner world,” which includes memories,
thoughts, dreams, desires, feelings, the external world is simply the
world of mountains and trees, of animals and men,. Every child
knows what is meant when we assert the existence of definite ob-
jects of tMs world; and we must insist that it really means absolutely
nothing more than what the child knows. We all know how to
verify the statement, say, that “there is a castle in the park outside
the city.” We act in certain ways and then if certain clearly describ-
able facts are experienced we say: “Yes, there really is a castle
there,” otherwise v/e say the statement was wrong, or a lie. And if
someone asks us: “Was the castle also there at night, when no one
saw it?” We answer: “Undoubtedly! For it would have been im-
possible to build it since this morning; furthermore the condition
of the building shows that not only was it there yesterday, but
for hundreds of years, hence before we were born.” Thus we pos-
sess quite definite empirical criteria with wMch to determine
whether houses and trees existed when we did not see them, and
whether they already existed before our birth, and whether they
will exist after our death. This means that the statement that those
things “exist independently of us” has a clear verifiable meaning,
and is obviously to be affirmed. We can very well distinguish em-
pirically tMngs of this sort from those that are only “subjective” and

I IVl ]

Positivism and Realism ,

^^dependent upon ns.’’ If, f 5 lay that the

I see a dark spot when I look f the waU is there

spot is there only when I look of this distinction is

even when I do not look at it. The venhcation or i

indeed quite easy, and both these statements say ]

tained in the verifications, and t/taken with the signification

Hence if the phrase external world is taken w«n me ^

si^Vly “®“°'biyt'w?have

In tte negative. There are, S aiv thinker

wten we1^fc°“f miuntSs and plants he would convince us that

n„rs:ieS. ^SSef fin ‘oppo.siho„ to —

r«1 If “ »?t' ts the

Seir theory and therefore the one must be real in the same sense
as the oth?r. The objectivity of fn no

same as that of

Srt3dor formm in Lct-'we aJe at last convinced that the
existence of even the most subtle “invisible things, assumed b> the
SSist S: S principle, verified exactly as is the reality of a tree

""in order to settle the dispute concerning realism it is of^ vej
.Treat importance to draw the physicist’s attention to the
his'.'xternal world is simplv nature, which also surrounds us in c y
iiie aS not the “transcendent world” of the metaphysic, aiu The

TrSf.:nrS’ ,rwf Sv? aSy’aaidT— h£

Tn instil that it must be by us. Atoms in Kant's system ha» no
transcendent reality, they are not “things in themselves. Hence the
vSSToM appeal to the Kantian philosophy; its arguments
£i only to the empirical external world which we all acknowledge.

[102]

morttz schlick

« .0 a tra««ad=a, wodd; his elactroas „„aphysi=a,

SlSHstSslrS

»hic^»p„a.=s .heTJ^^fhS '.he L'SsISr “

held b; sf S' oSr,„‘ L'o”: ::vrs^?

=“£=t:P«P''5S

elsewhere „a„v .™e?bSSUordra"„d”te

S “CS lFIt -r-

t ^”fbf ~Zfi;

siHSS-^ - - “

theticaliy something unknowable. For fte^^ m^sralwavrb?

Positivism and Realism [ 103 ]

have the property of fulfilling this function, and must be so con-
stituted that it is justified by those reasons. But in just this 'way cer-
tain statements are made regarding the assumed entity and these
express our knowledge of it. And of course they contain complete
knowledge of it. For only that can be assumed hypothetically for
which there are grounds in experience.

Or does the ‘'realistic” scientist want to designate the theory of
objects which are not directly experienced as a metaphysical hypoth-
esis for some other reason than that of their unknowableness, which is
not under consideration at all? To this he will perhaps answer affirma-
tively. In fact we learn from numerous statements in the literature that
the physicist does not add any statement of its unknowable char-
acter to his affirmation of a transcendent world; quite the contrary,
he is rightly of the opinion that the nature of the extra-mental things
is correctly represented by his equations. Thus the external world
of the physical realist is not that of traditional metaphysics. He uses
the technical term of the philosopher, but what he means by it has ap-
peared to us to be nothing but the external world of everyday life,
whose existence no one, not ex^en the “positivist,” doubts.

What, then, is that other reason which leads the “realist” to
conceive his external world as a metaphysical hypothesis? Why does
he want to distinguish it from the empirical external world which
we have described? The answer to this question leads us back again
to an earlier point in our discussion. The physical “realist” is quite
satisfied with our description of the external world except in one
point: he does not believe that we have granted it enough reality. It
is not because it is unknowable, or for any such reason that he
thinks his “external world” differs from the empirical, but only be-
cause a different, higher reality pertains to it. This often shows itself
in his language; the word “real” is frequently reserved for that ex-
ternal world in contrast with the merely “ideal,” “subjective” con-
tents of consciousness, and in opposition to mere “logical” construc-
tions, “positivism” being reproached with the attempt to reduce
reality to such logical constructs.

But the physical realist, too, feels obscurely that, as we know,
reality is not a “predicate,” hence he cannot well pass from our
empirical to his transcendent external world by ascribing to it, in
addition to the characteristics which we also attribute to physical ob-
jects, the characteristic of “reality.” Nevertheless he expresses him-
self in this way; and this illegitimate leap, which carries him beyond
the realm of significance, would indeed be “metaphysical,” and will
be felt by him to be such.

liii

f >i«' |i ■'

Is' I
f ^ M ,'

r-; fl 04 ]

';,H mokitz schlick

3 S

:ii “W-

only in the “given ” and that ■ f ^ obpct, can be tested

tions can be formulated and meaimg of all proposi-

- given— this principle is mislak^y*^ “nceiwd nsV^t Ss'’l°fl*'''

that the meanin<' of an existential^ ^ the contrary:

by mere proportions of the fn sense exhausted

that definite experience will occu™’ fthSe conditions

an infinite set according to our viei constituting

beyond ail this in somethino- <^ic u* I Hieaning lies

•■independeoTeristSS '^s 4™ ■ c »y.

■0 vAich out principle 'fails to do j^tke

do these phras« •°ndepenS'e 3 kttnt"''aL'^“tjr‘‘“ d
’»ea„? In other words: what verMlt Sff “ "“'“ndent bemg”

heves himself to “de^r *K' ^^iferentl^ from one who be-

sei^'e the stirrv^ sensations.” The former will ob-

own puny nature an^^^ conscious of his

of the world with very different^eer^*^”^' grandeur

S o/ ht° wn'-fe"'*' ““““ - Sef; W

self'r; Ss tasb devote him-

knowiedge of Ihe external" "" '""dsfaction in the

cause he believes S To h T ? be-

structions. ^ith his own con-

that^soSSrTtoThTtehTvio^o??^ comment. Let us assume

difference such as has been deco ^‘ddirits Acre does exist a

of course be M otevable difff^ T
gts on expressmg this diffenence brsV„“/S'ore*„fT'“>'

even, Ae nreuAug 5 S ItaTemen, wo '>■“

observe in fte behavior of Ae two men ’"lAaf “*

reahty. or •■rianscendent be“,ror“h“,?™f:x;",:

' positivism and Realism [ ]

miglit choose to employ, mean here simply certain states of feeling,
which occur in the men when they observe the world, or make state-
ments about it, or philosophize. It is, indeed, the case that the use of
the words “independent existence,” “transcendent reality,” etc., is
simply and only the expression of a feeling, of a psychological attitude
of the speaker (this, moreover, may, in the final analysis, be true of all
metaphysical propositions). If someone assures us that there is a
real external world in the trans-empirical sense of the word, he of
course believes himself to have communicated some truth about the
world. But in actual fact, his words express something very different;
they merely express certain feelings which give rise to various lin-
guistic and other reactions on his part.

If this self-evident point requires any further emphasis I should
like to call attention to the fact — and with the greatest stress on the
seriousness of what is said — that the non-metaphysician is not dis-
tinguished from the metaphysician by, say. the absence in him of
those feelings which the other expresses in terms of the statements
of a realistic philosophy, but only by the fact that he recognizes that
these statements simply do not have the meaning they seem to have,
and are therefore to be avoided. The non-metaphysician will express
these same feelings in a dlffereni way. In other words: the contrast
drawn in the first answer of the "realisr" between the two types of
thinkers was misleading and unjust. If one is unfortunate enough
not to feel the sublimity of the starry heavens sometiiing other than
a logical analysis of the concepts of reality and external world is
to be blamed. To assume that the opponents of metaphysics are
unable justly to comprehend, say, the greatness of Copernicus, be-
cause in a certain sense the Ptolemaic view represents the empirical
facts as w'eH as the Copernican. seems to me to be as strange as to
believe that the “positivist” cannot be a good parent because accord-
ing to his theory his children are merely complexes of his own sense-
impressions, and it is therefore senseless to take measures for their
welfare after his death. No: the world of the non-metaphysician is
the same world as that of all other men; it lacks nothing which is
needed to bestow meaning on all the propositions of science and
the whole conduct of life. He merely avoids adding meaningless state-
ments to his description of the world.

We come now to the second answer which can be given to the
question concerning the meaning of the assertion of a transcendent
reality. It consists in granting that it makes no difference at all for
experience whether or not one assumes something further to exist
behind the empirical world, that metaphysical realism therefore

[ 106 ]

unverifiable. Hence one cannot in-
dicate any further what is meant by this assertion; but nevertheless

Uout veScatS?^"’ ^

nothing but the view, criticized in the previous section
Uon ^^“Srmerf “ P“P»sitioii has aothmg to do with its verifica-

special case, perefore we must say: you designate here by ex-
rttpce or reality something which simply cannot in any wJy be

make sense. We shall noi quarrel with you over this point. But this

can in no admission just made this sense

can in no way become evident, it cannot be expressed in any written
or spoken communication, nor by any gesture or conduct For if

S Ind ,r IH™ ""m? "“Pirical

fact, and the world would be d/fferent if the proposition “there is

an extpnal world” were true, from what it would £ if it were false

This difference would then constitute the meaning of th^p^ase

be an empirical meaning- that

4ich iTk^ empirical world,

wnich, like all human beings, we also acknowledge.^ Even to speak

of any other world is logically impossible. There can be no dLcus

s.on conccmms ic, to, , noo-veriliable existence c^o. ento meat

liera 'him'self™/ ptoposiiion. Whoever still believes^, be-

heves himself to believe— m it must do so only silently Ar<mments
can relate only to what can be said. ^ r^uments

discussion may be summarized as follows-

seems to m^tn h “positivistic” tendency

^ems to me to be the pnnciple that the meaning of every proposi-

tion is completely eptained within its verification in the ^

IS principle has seldom been clearly apparent within that
general tendency, and has so frequently been mkef 4th so many un
tenable propsitions that a logical purification is necessary l/one
result of the purification positivism, which wuld per-
^ justifiable, at least a differentiating adjective must

?ied?-S^4“44i^™ “logistic poSm”

to m^ to

XXVtf/®(193lf^^e ^ Joumal of Philosophy, Vol.

VoL XIII, Ser. B (Tu^ 19301 Universilalis Aboensis,

VmversUii, GoJorg ’ ^ Schrifien der

Positivism and Realism [ ]

2) This principle does not mean and does not imply that only
the given is real. Such an assertion does not make sense.

3) Hence also, consistent empiricism does not deny the existence
of an external world; it merely points out the empirical meaning of
this existential proposition.

4) It is not a “Theory of As If.” It does not assert that every-
thing behaves as if there were physical independent bodies; but for
it, too, everything is real which the non-philosophizing scientist calls
real. The subject-matter of physics is not sensations, but laws. The
formulation, used by some positivists, that bodies are only “com-
plexes of sensations” is therefore to be rejected. What is correct is
only that propositions concerning bodies are transformable into
equivalent propositions concerning the occurrence of sensations in
accordance with laws.

5) Hence logical positivism and realism are not in opposition;
whoever acknowledges our fundamental principle must be an em-
pirical realist.^

6) An opposition exists only between the consistent empiricist
and the metaphysician, and indeed no more against the realist than
against the idealist metaphysician (the former has been referred to
in our discussion as “realist” in quotation marks).

7) The denial of the existence of a transcendent externai world
would be just as much a metaphysical statement as its affirmation.
Hence the consistent empiricist does not deny the transcendent
world, but shows that both its denial and afSnnation are meaningless.

This last distinction is of the greatest importance. I am con-
vinced that the chief opposition to our view derives from the fact
that the distinction between the falsity and the meaninglessness of
a proposition is not observed. The proposition “Discourse concern-
ing a metaphysical external world is meaningless” does not say;
“There is no external world,” but something altogether different.
The empiricist does not say to the metaphysician “what you say is
false,” but, “what you say asserts nothing at all!” He does not con-
tradict him, but says “I don’t understand you.”

4. On this point and on the entire subject of the present essay the reader is also
referred to Hans Cornelius’ “Zur Kritik der Wissenschafllichen Grundbegriife/’
Erkenntnis, Vol. 11. The formulations there are, however, open to objections. See
also the splendid remarks in Chapter X of PhilHp Frank’s fine work. Das Kausal-
gesetz und seine Grenzen, and Rudolf Carnap’s Scheinprobleme der Philosophic,

5

The Empiricist Criterion

of Meaning

BY CARL G. HEMPEL

1. Introduction

The fundamental tenet of modem empiricism is the view that
all non-analytic knowledge is based on experience. Let us call this
thesis the principle of empiricism.^ Contemporar>' logical empiricism
has added- to it the maxim that a sentence makes a cognitively mean-
ingful assertion, and thus can be said to be either tme or false, only
if it is either (1) analytic or seli-contradictorv' or (2) capable, at
least in principle, of experiential test. According to this so-called
empiricist criterion of cognitive meaning, or of cognitive significance,
many of the formulations of traditional metaphysics and large parts
of epistemology are devoid of cognitive significance — however rich
some of them may be in non-cognitive import by virtue of their
emotive appeal or the moral inspiration they offer. Similarly certain
doctrines which have been, at one time or another, formulated within
empirical science or its border disciplines are so contrived as to be
incapable of test by any conceivable evidence; they are therefore
qualified as pseudo-hypotheses, which assert nothing, and which

This article first appeared in Vol. 4 of Revue Internationale de Philosophie (1950).
It is republished here with the kind permission of Professor Hempel and the editor
of that journal.

t- This term is used by Benjamin (2) in an examination of the foundations of
empiricism. For a recent discussion of the basic ideas of empiricism see Russell (27),
Part Six.

2. In his stimulating article, “Positivism,” W, T. Siace argues, in effect, that the
testability criterion of meaning is not logically entailed by the principle of empiricism.
(See (29), especially section 11.) This is correct: according to the latter, a sentence
expresses knowledge only if it is either analytic or corroborated by empirical evi-
dence; the former goes further and identifies the domain of cognitively significant
discourse with that of potential knowledge; i. e., it grants cognitive import only to
sentences for which — unless they are either analytic or contradictorv' — a test by
empirical evidence is conceivable.

S

[ 108 ]

The Empiricist Criterion of Meaning [ ]

therefore have no explanatory or predictive force whatever. This
verdict applies, for example, to the neo-vitalist speculations about
entelechies or vital forces, and to the “teiefinalist hypothesis*' pro-
pounded by Lecomte du Nouy,^

The preceding formulations of the principle of empiricism and
of the empiricist meaning criterion provide no more, however, than
a general and rather vague characterization of a basic point of view,
and they need therefore to be elucidated and amplified. And while
in the earlier phases of its development, logical empiricism was to
a large extent preoccupied with a critique of philosophic and scien-
tific formulations by means of those fundamental principles, there
has been in recent years an increasing concern with the positive tasks
of analyzing in detail the logic and methodology of empirical science
and of clarifying and restating the basic ideas of empiricism in the
light of the insights thus obtained. In the present article, I propose
to discuss some of the problems this search has raised and some of
the results it seems to have established.

2. Changes in the Testability Criterion

OF Empirical Meaning

As our formulation shows, the empiricist meaning criterion lays
down the requirement of experiential testability for those among
the cognitively meaningful sentences which are neither analytic nor
contradictory; let us call them sentences with empirical meaning,
or empirical significance. The concept of testability, which is to
render precise the vague notion of being based — or rather baseable
— on experience, has undergone several modifications which refiect
an increasingly refined analysis of the structure of empirical knowl-
edge. In the present section, let us examine the major stages of this
development.

For convenience of exposition, we first introduce three auxiliar}^
concepts, namely those of observable characteristic, of observation
predicate, and of observation sentence. A property or a relation of
physical objects will be called an observable characteristic if, under
suitable circumstances, its presence or absence in a given instance
can be ascertained through direct observation. Thus, the terms
“green,’’ “soft,” “liquid,” “longer than,” designate observable char-
acteristics, while “bivalent,” “radioactive,” “better electric con-
ductor,” and “introvert” do not. Terms which designate observable
characteristics will be called observation predicates. Finally, by an

3. CL (19), Ch. XVL

f no 1

^ CARL G. HEMPEL

observation sentence we shaU understand any sentence which— cor-
rectly or incorrectly — asserts of one or more specifically named ob-
jects that they have, or that they lack, some specified observable
1 following sentences, for example, meet this con-
toon. The Eiffel Tower is taUer than the buildings in its vicinity ”
Die pointer of this mstrument does not cover the point marked
3 on the scale, and even, “The largest dinosaur on exhibit in New
York s Museum of Natural History had a blue tongue”; for this last
sentence assies to a specified object a characteristic— having a blue
of such a kind that under suitable circumstances
’ Chow dog) its presence or absence can

by direct observation. Our concept of obser^’ation
sentence is mtended to provide a precise interpretation of the va^e
n asserting something that is “in principle” ascer-

tainable by direct observation, even though it mav happen to be
actually incapable of bemg observed bv mvself. perhaps also bv
my contemporaries, and possibly even bv anv human bein- who
ever lived or wdl live. Any evidence that might be adduced In the
test of an empirical hypothesis may now be thouaht of as beincf ex-
pressed in observation sentences of this kind.^ “ “

Changes in the conception 6f testabilitv,
and thus of empmcal meaning. In the earlv davs of the Vienna
Urcie a sentence was said to have empirical raeaninc if it was
capable, at least m pnnciple, of complete verification bv observa-
tional evidence; i.e., if observational evidence could be' described
which, if actually obtained, would condusivelv establish the truth
of the sent ence.^' With the help of the concept of obser^■ation

sgsMItlsilSPi

Ongmaliy, the permissible evidence was meant to be resiricrp^ m ic

obMrvable by the speaker and perhaps his fellow-beings during ibeir Ufetiii”^

tongue of the largest dinosaur m New York’s Museum of Natural History Wue

..The Empiricist Criterion of Meaning [ ]

fence, we can restate this requirement as follows: A sentence S has
empirical meaning if and only if it is possible to indicate a finite
set of observation sentences, Oi, O 2 , . . * , On, such that if these
are true, then S' is necessarily true, too. As stated, however, this
condition is satisfied also if S is an analytic sentence or if the given
observation sentences are logically incompatible with each other. By
the following formulation, we rule these cases out and at the same
time express the intended criterion more precisely:

(2.1) Requirement of complete verifiability in principle: A sen-
tence has empirical meaning if and only if it is not analytic and
follows logically from some finite and logically consistent class of
observation sentences.®

or black” is completely verifiable in our sense; for it is a logical consequence of the
Sentence S^, “The tongue of the largest dinosaur in New York’s Museum of Natural
History was blue”; and this is an observation sentence, as has been shown above.

And if the concept of verifiability in principle and the more general concept of
confirmability in principle, which will be considered later, are construed as referring
to logically possible evidence as expressed by observation sentences, then it follows
similarly that the class of statements which are verifiable, or at least confirmable, in
principle includes such assertions as that the planet Neptune and the Antarctic
Continent existed before they were discovered, and that atomic warfare, if not
checked, may lead to the extermination of this planet. The objections which Russell
(cf. (27), pp. 445 and 447) raises against the verifiability criterion by reference to
those examples do not apply therefore if the criterion is understood in the manner
here suggested. Incidentally, statements of the kind mentioned by Russell, which are
not actually verifiable by any human being, were explicitly recognized as cognitively
significant already by Schlick (in (28), Part V). who argued that the impossibility
of verifying them was “merely empirical.” The characterization of verifiability with
the help of the concept of observation sentence as suggested here might serve as a
more explicit and rigorous statement of that conception.

6. As has frequently been emphasized in empiricist literature, the term “veri-
fiability” is to indicate, of course, the conceivability, or better, the logical possibility
of evidence of an observational kind which, if actually encountered, would consti-
tute conclusive evidence for the given sentence; it is not intended to mean the
technical possibility of performing the tests needed to obtain such evidence, and
even less does it mean the possibility of actually finding directly observable phe-
nomena which constitute conclusive evidence for that sentence — which would be
tantamount to the actual existence of such evidence and would thus imply the truth
of the given sentence. Analogous remarks apply to the terms “falsifiabiiiiy” and
“confirmability.” This point has been disregarded in some recent critical discussions
of the verifiability criterion. Thus, e.g., Russell (cf. (27), p. 448) construes verifia-
bility as the actual existence of a set of conclusively verifying occurrences. This
conception, which has never been advocated by any logical empiricist, must naturally
turn out to be inadequate since acording to it the empirical meaningfulness of a
sentence could not be established without gathering empirical evidence, an J more-
over enough of it to permit a conclusive proof of the sentences in question! It is
not surprising, therefore, that his extraordinary interpretation of verifiability leads
Russell to the conclusion: “In fact, that a proposition is verifiable is itself not
verifiable” (/. c.) Actually, under the empiricist interpretation of complete veri-
fiability, any statement asserting the verifiability of some sentence S whose text is
quoted, is either analytic or contradictory; for the decision whether there exists a
class of observation sentences which entail S, i. e., whether such observation sen-
tences can be formulated, no matter whether they are true or false — that decision

[ 112 ]

™ . . . CARL G. HEMPEL

cntenon, however, has several serious defects. The first of
those here to be mentioned has been pointed out by various writers:

versal fom, out aU sentences of uni-

l^s; for these cannot be conclusively verified by any^ finite“set of
observational data. And since sentences of this ipfcSitute f
integral part of scientific theories, the verifiability requirement must
Ij regarded as overly restrictive in this respect SiSy “he cn
tenon disqualifies all sentences such as “For any subst^ce there

^“versal andTStentiS

quantifiers (i.e., occurrences of the terms “all” -fu *

equivalents); for no sentences of toS ct.

from any fimte set of observation sentences ^

nIs" ienteSTuS rs^'^he'ltLlls "pXT'

irnattn'tvr«r.r'’“'“ “ «

clearly, the empiricist criterion of meLn. is not intended conn

SmS p^s: “/e'ShSj ro-s.

{c) Let P be an observation predicate. Then the purelv ev

Sfs r'““ ("There exists at leas' one thLi

Inv h P^pecly P") IS completely verifiable, for it follows fsor^
any ofcervatton sentence asserting „t some particular oWe" tSm
« has the property P, But its denial , being equivalent to the Liversal

" information whate^

proposition is said to be ‘true’ when it is ‘terifirw*^ positivists: “A

know the conditions which when reali-^d win «■. when we

Ay^r) ” (cf. ( 31 ), p. 145). The quoted thesis which “at '

logical positivist, including Aver is in ’ir. * n’ anv

describe conditions which^ if ^realized would

the Chrysler Building is painted a b^iphf v n '^ sentence “The outside of
verifying conditions for its^ denial* hencf ^ similarly, we can describe

sentence and its denial would have to he^ ^ quoted principle, both the

under discussion does not accord with ered true. Incidentally, the passage

i-c., p. 40 , that verifiabiSty IS i^Lde^ observation,

which shows that verifiabiUty is meant to h.- a the meaning of a sentence —

than of truth. ^ ^ criterion of cognitive significance rather

The Empiricist Criterion of Meaning [ ]

sentence “(x) ^ P(x)” (“Nothing has the property P”) is clearly
not completely verifiable, as follows from comment {a) above.
Hence, under the criterion (2.1), the denials of certain empirically
— and thus cognitively — significant sentences are empirically mean-
ingless; and as they are neither analytic nor contradictory, they are
cognitively meaningless. But however we may delimit the domain
of significant discourse, we shall have to insist that if a sentence falls
within that domain, then so must its denial. To put the matter more
explicitly: The sentences to be qualified as cognitively meaningful
are precisely those which can be significantly said to be either true
or false. But then, adherence to (2.1) would engender a serious
dilemma, as is shown by the consequence just mentioned. We would
either have to give up the fundamental logical principle that if a
sentence is true or false, then its denial is false or tnie, respectively
(and thus cognitively significant); or else, we must deny, in a manner
reminiscent of the intuitionistic conception of logic tind mathematics,
that “(x) P(x)’' is logically equivalent to the negation of

‘‘(Ex) P (x).” Clearly, the criterion (2.1), which has disqualified
itself on several other counts, does not warrant such drastic measures
for its preservation; hence, it has to be abandoned.’^

Strictly analogous considerations apply to an alternative criterion,
which makes complete falsifiability in principle the defining char-
acteristic of empirical significance. Let us formulate this criterion
as follows: A sentence has empirical meaning if and only if it is
capable, in principle, of complete refutation by a finite number of
observational data; or, more precisely:

(2,2) Requirement of complete falsifiabiUty in principle: A sen-
tence has empirical meaning if and only if its denial is not anal}l:ic
and follows logically from some finite logically consistent class of
observation sentences.^

7. The arguments here adduced against the verifiability criterion also prove the
inadequacy of a view closely related to it, namely that two sentences have the same
cognitive significance if any set of observation sentences which would verify one
of them would also verify the other, and conversely. Thus, e. g., under this criterion,
any two general laws would have to be assigned the same cognitive significance, for
no general law is verified by any set of observation sentences. The view just referred
to must be clearly distinguished from a position which Russell examines in his
critical discussion of the positivistic meaning criterion. It is “the theory that two
propositions whose verified consequences are identical have the same significance”
((27), p. 448). This view is untenable indeed, for what consequences of a statement
have actually been verified at a given time is obviously a matter of historical acci-
dent which cannot possibly serve to establish identity of cognitive significance. But
I am not aware that any logical positivist ever subscribed to that “theory.”

8. The idea of using theoretical falsifiability by observational evidence as the
“criterion of demarcation” separating empirical science from mathematics and logic
on the one hand and from metaphysics on the other is due to K. Popper (cf. (22),

[ 114 ] CARL G. HEMPEL

This criterion qualifies a sentence as empirically meaningful if
its denial satisfies the requirement of complete verifiability; as is to
be expected, it is therefore inadequate on similar grounds as the
latter:

(a) It rules out purely existential hypotheses, such as “There
exists at least one unicorn,” and ail sentences whose formulation
calls for mixed — i.e., universal and existential — quantification; for
none of these can possibly be conclusively falsified by a finite number
of observation sentences.

(b) If a sentence S is completely falsifiable whereas N is a
sentence which is not, then their conjunction, S.N. (i.e., the ex-
pression obtained by connecting the two sentences by the word
“and”) is completely falsifiable; for if the denial of S is entailed
by some class of observation sentences, then the denial of S.N. is,
a fortiori, entailed by the same class. Thus, the criterion allows
empirical significance to many sentences which an adequate empiri-
cist criterion should mle out, such as, say “All swans are white and
the absolute is perfect.”

(c) If “P” is an observation predicate, then the assertion that
all things have the property P is qualified as significant, but its
denial, being equivalent to a purely existential hypothesis, is dis-
qualified (cf. (a)). Hence, criterion (2.2) gives rise" to the same
dilemma as (2.1).

In sum, then, interpretations of the testability cnterion in terms
of complete verifiability or of complete faisifiability are inadequate
because they are overly restrictive in one direction and overly in-
clusive in another, and because both of them require incisive changes
in the fundamental principles of logic.

Several attempts have been made to avoid these difficulties by
constming the testability criterion as demanding merely a partii
and possibly indirect confirmability of empirical hypotheses by ob-
servational evidence.

(2.3) A formulation suggested by Ayer® is characteristic of
these attempts to set up a clear and sufficiently comprehensive
criterion of confirmability. It states, in effect, that a sentence S has
empirical import if from S in conjunction with suitable subsidiary

section 1-7 and 19-24; also see (23), voL II, pp. 282-285). Whether Popper would
subscribe to the proposed restatement of the faisifiability criterion, I do not know.

9. ( 1 ) , Ch. I. — ^The case against the requirements of verifiability and of faisifia-
bility, and favor of a requirement of partial confirmability and disconfirmability is
very clearly presented also by Pap in (21), Chapter 13.

The Empiricist Criterion of Meaning [ ]

hypotheses it is possible to derive observation sentences which are
not derivable from the subsidiary hypotheses alone.

This condition is suggested by a closer consideration of the
logical structure of scientific testing; but it is much too liberal as
it stands. Indeed, as Ayer himself has pointed out in the second edi-
tion of his book. Language, Truth, and Logic , his criterion allows
empirical import to any sentence whatever. Thus, e.g., if S is the
sentence “The absolute is perfect,” it suffices to choose as a sub-
sidiary hypothesis the sentence “If the absolute is perfect then this
apple is red” in order to make possible the deduction of the ob-
servation sentence “This apple is red,” which clearly does not fol-
low from the subsidiary hypothesis aloneT^

(2.4) To meet this objection, Ayer has recently proposed a
modified version of his testability criterion. The modification re-
stricts, in effect, the subsidiary' hypotheses mentioned in (2.3) to
sentences which are either analytic or can independently be shown
to be testable in the sense of the modified criterion.^-

But it can readily be shown that this new criterion, like the re-
quirement of complete falsifiability, allows empirical significance
to any conjunction S.N, w^here S satisfies Ayers criterion while N
is a sentence such as “The absolute is perfect,” which is to be dis-
qualified by that criterion. Indeed: whatever consequences can be

10. (l), 2d ed., pp. 11-12.

11. According lo Siace (cf. (29), p. 218), the criterion of partial and indirect
testability, which he calls the positivist principle, presupposes (and thus logically
entails) another principle, which he terms the Principle oj Observable Kinds: “A
sentence, in order to be signiheant, must assert or deny facts which are of a kind
or class such that it is logically possible directly to observe some facts which are
instances of that class or kind. And if a sentence purports to assert or deny facts
which are of a class or kind such that it would be logically impossible directly lo
observe any instance of that class or kind, then the sentence is non-significant.” T
think the argument Siace offers to prove that this principle is entailed by the re-
quirement of testability is inconclusive (mainly because of the incorrect tacit assump-
tion that "on the transformation view of deduction,” the premises of a valid deductive
argument m.usi be necessary conditions for the conclusion (/. c., p. 225). Without
pressing this point any further, I should like to add here a remark on the principle
of observable kinds itself. Professor Stace does not say how we are to determine
what “facts” a given sentence asserts or denies, or indeed whether it asserts or
denies any “facts” at all. Hence, the exact import of the principle remains unclear.
No matter, however, how one might choose the criteria for the factual reference of
sentences, this much seems certain: If a sentence expresses any fact at all, say /,
then it satisfies the requirement laid down in the first sentence of the principle; for
we can always form a class containing / together with the fact expressed by some
observ'ation sentence of our choice, which makes / a member of a class of facts
at least one of which is capable, in principle, of direct observation. The first part
of the principle of obsert’abie kinds is therefore all-inclusive, somewhat like Ayer’s
original formulation of the empiricist meaning criterion.

12. This restriction is expressed in recursive form and involves no vicious circle.
For the full statement of Ayer’s criterion, see (1), second edition, p. 13.

CARL G. HEMPEL

[ 116 ]

deduced from S with the help of permissible subsidiary hypotheses
can also be deduced from S.N. by means of the same subsidiary
hypotheses, and as Ayer’s new criterion is formulated essentially in
terms of the deducibility of a certain type of consequence from
the given sentence, it countenances S.N together with S. Another
difficulty has been pointed out by Professor A. Church, who has
shown^^ that if there are any three observation sentences none of
which alone entails any of the others, then it follows for any sentence
S whatsoever that either it or its denial has empirical import ac-
cording to Ayer’s revised criterion.

3. Translatability into an Empiricist Language

AS A New Criterion of Cognitive Meaning

I think it is useless to continue the search for an adequate cri-
terion of testability in terms of deductive relationships to observa-
tion sentences. The past development of this search — of which we
have considered the major stages — seems to warrant the expectation
that as long as we try to set up a criterion of testability for indi-
vidual sentences in a natural language, in terms of logical relation-
sliip to observation sentences, the result will be either too restrictive
or too inclusive, or both. In particular it appears likely that such
criteria would allow empirical import, in the manner of {2A)(b)
or of (2.2) (h), either to any alternation or to any conjunction of
two sentences of which at least one is qualified as empirically mean-
ingful; and this peculiarity has undesirable consequences because the
liberal grammatical rules of English as of any other natural lan-
guage countenance as sentences certain expressions (‘The absolute
is perfect” was our illustration) wmich even by the most liberal em-
piricist standards make no assertion whatever; and these would
then have to be permitted as components of empirically significant
statements.

The predicament would not arise, of course, in an artificial
language whose vocabulary and grammar were so chosen as to pre-
clude altogether the possibility of forming sentences of any kind
which the empiricist meaning criterion is intended to rule out. Let
us call any such language an empiricist language. This reflection
suggests an entirely different approach to our problem: Give a gen-
eral characterization of the kind of language that would qualify as
empiricist, and then lay down the following

(3.1) Translatability criterion of cognitive meaning: A sentence

13, Church (11).

The Empiricist Criterion of Meaning [ 117 ]

has cognitive meaning if and only if it is translatable into an em-
piricist language.

This conception of cognitive import, while perhaps not explicitly
stated, seems to underlie much of the more recent work done by
empiricist writers; as far as I can see it has its origin in Carnap’s
essay, Testability and. Meaning (especially part IV).

As any language, so also any empiricist language can be char-
acterized by indicating its vocabulary and the rules determining its
logic; the latter include the syntactical rules according to which sen-
tences may be formed by means of the given vocabulary. In effect,
therefore, the translatability^ criterion proposes to characterize the
cognitively meaningful sentences by the vocabulary out of v/hich they
may be constructed, and by the syntactical principles governing their
construction. What sentences are singled out as cognitively significant
will depend, accordingly, on the choice of the vocabulary and of
the construction rules. Let us consider a specific possibility:

(3.2) We might qualify a language L as empiricist if it satisfies
the following conditions:

(a) The vocabulary of L contains:

(1) The customary^ locutions of logic which are used in the
formulation of sentences; including in particular the expressions '‘not,”
“and,” “or,” “if . . . then . . . “all.” “some.” “the class of all
things such that . . . “. . . is an element of class . . .”;

(2) Certain observation predicates. These will be said to con-
stitute the basic empirical vocabulary’ of L;

(3) Any expression definable by means of those referred to
under (1) and (2).

(b) The rules of sentence formation for L are those laid down
in some contemporary’ logical system such as Principia Mathematica,

Since all defined terms can be eliminated in favor of primitives,
these rules stipulate in effect that a language L is empiricist if all
its sentences are expressible, with the help of the usual logical locu-
tions, in terms of observable characteristics of physical objects. Let
us call any language of this sort a thing-language in the narrower
sense. Alternatively, the basic empirical vocabulary of an empiricist
language might be construed as consisting of phenomenalistic terms,
each of them referring to some aspect of the phenomena of per-
ception or sensation. The construction of adequate phenomenalistic
languages, however, presents considerable difiiculties,^^ and in recent
empiricism, attention has been focussed primarily on the potential-

14. Important contributions to the problem have been made by Carnap (5) and
by Goodman (15).

I

f I CARL G. HEMPEL

the descriS 5 aatv^ i? ; iMd lhemsd,es more direoly ,o
voked in are ,cs. of scieSc hypSEer'’'

the trankTaWUty SSS'

00. ^ O^r r£“S '^feorSt- 3 ^

of the terms “aU” and “Sl- h" i.e., for the use

is generally excluded from the r^l)' of quantified statement

course; cognitively significant dis-

do.o«'d

nificant; ^ mi^ht be qualified as cognitively sig-

M<irfeLS,“o!“?‘dentarot 7°eMe“' ™‘=' ““tom^S to Pmtciph
of L. Honco, the mStli, "8“'" » '=”K”oe
tequenco which is eotaiied by 4,™^ °f 'S'*,;” ‘I’VT

attribute cognitive me^nin^*^toT//^"^^^’ criterion does not

“The absolute s Set’’ fnd

translated into an emS cisrl.^l cannot be

not definable by means of nurefo1nc®“ i are

terms. ^ ^°g'^al expressions and observation

^oblem of Disposition Terms
AND OF Theoretical Constructs

aiso'iS’pmtesS"t” "«ri«ivo-as toe, incidentally

cohsiderataTempaSsUailT,;”' ''^'=1“ ””” ‘=1'' fo^

(3.2). then, as liTe^S"' “ ““ordanee with

allows cognitive import to a sentence onM O-D

terms are explicitly definable bv ^ constitutive empirical

as we shall a"rgu. p.2«2y miy e™s1 B«

are not so definable^ hence dte'diterio. Snfdtbig'^fjtj'S:

The Empiricist Criterion of Meaning [ 119 ]

as devoid of cognitive import, all scientific hypotheses containing
such terms — an altogether intolerable consequence.

The concept of temperature is a case in point. At first glance, it
seems as though the phrase “Object x has a temperature of c degrees
centigrade,” or briefly “T(x) =c” could be defined by the follow-
ing sentence, (D): T(x) — c if and only if the following condition
is satisfied: If a thermometer is in contact with x, then it registers c
degrees on its scale.

Disregarding niceties, it may be granted that the denniens given
here is formulated entirely in reference to obser\'abIes. However, it
has one highly questionable aspect. In Principia Mathemntica and
similar systems, the phrase “if p then is construed as being synon-
ymous with “not p or and under this so-called material inter-

pretation of the conditional a statement of the form “if p then
is obviously true if (though not only if) the sentence standing in
the place of is false. If, therefore, the meaning of “if . . .
then . . in the definiens of (D) is understood in the material
sense, then that definiens is true if (though not only if) x is an object
not in contact with a thermometer — no matter what numerical value
we may give to c. And since the definiendum would be true under
the same circumstances, the definition (D) would qualify as true
tlie assignment of any temperature value whatsoever to any object
not in contact with a thermometer! Analogous considerations apply
to such terms as “electrically charged,” “magnetic,” “intelligent,”
“electric resistance,” etc., in short to aU disposition terms, i.e., terms
which express the disposition of one or more objects to react in a
determinate way under specified circumstances. A definition of such
terms by means of observation predicates cannot be effected in the
manner of (D), however natural and obvious a mode of definition
this may at first seem to be.^^

There are two main directions in which a resolution of the diffi-
culty might be sought. On the one hand, it could be argued that
the definition of disposition terms in the manner of (D) is perfectly
adequate provided that the phrase “if . . . then . . .” in the definiens
is construed in the sense it is obviously intended to have, namely
as implying, in the case of (D), that even if x is not actually in
contact with a thermometer, still if it were in such contact, then the
thermometer would register c degrees. In sentences such as this,
the phrase “if . . . then ...” is said to be used counterfactually;

15. This difficulty in the definition of disposition terms was first pointed out
and analyzed by Camap (in (6); see esp. section 7).

[ 120 ]

.... . CARL G. HEMPEL

ditionar sense, which implies a counterfactual con-
araonal, that the defimens of (D) would have to be constnied Thic
suggestion would provide an answer to the problem of definin<» dis

account of the exact meamng of counterfactual conditionals seems

he^tatua S a diSl y I.”

the status of a program rather than that of a solution. The lack of

nfn counterfactual conditionals is aU the more de-

plorable as such a theory is needed also for the analysis of the con

A H in empirical science and of certain related ideas

^ ?n ffr “ the logic and methodology of science

is --“S

Tf o fh ^ pieans or the following reduction sentence fRV

If a thermometer is in contact with an Sbject x, tLn fS - c if
and only If the thermometer registers c degmes. ^

his rule, in which the conditional mav be constru<>d in th-

n^triThTfoS^^if “temperaturrS:^^^^^^^^^

gradually extended to cases not covered in K^r ^

rurther redumion sentences, which reflect the meLuram»nrof 10^
perature by devices other than thermometers.

ivcduction sentences tlms provid'^. a m^anc fr\r
mulation^f what is commonly referred to as operational d^finhb.ns°is

no avan'^oVr C. L Lewis would be of

unWi^:^srde^a°d:/wTin^

based on empirical laws. For recent discuSfons ofThe m relationship, i. e., one
see Langford (18); Lewis (20) no % 1 n oin ^ rh - ^ counterfactuals
(14); Reichenbach (26), Chapter VIII- Goodman

Popper (24). '-napter Vill, Hempel and Oppenheim (16), Part III;

found in Camap^(7L^’Part'^'in The^na^al^Tfi^^'r" centra! idea may be

the expression “T(x) = c” illustrates onlv^th^ formulated above for

the so-called bilateral reducliofseSencI ^

see.1or°e” -- ‘^-eloped by Bridgman.

i The Empiricist Criterion of Meaning [111 ]

j- At the same time, they show that the latter are not deiiiiitions in
I the strict sense of the word, but rather partial specifications of
I meaning,

i The preceding considerations suggest that in our characteriza-
I tion (3.2) of empiricist languages we broaden the provision ^ (3)
j by permitting in the vocabulary of L all those terms whose mean-
ing can be specified in terms of the basic empirical vocabular}' by
I means of definitions or reduction sentences. Languages satisfying
I this more inclusive criterion will be referred to as thing-languages
I in the wider sense.

I If the concept of empiricist language is broadened in this man-
ner, then the translatability criterion (3.1) covers — as it should —
also all those statements whose constituent empirical terms include
‘‘empirical constructs,” i.e., terms which do not designate observ^ables,
but which can be introduced by reduction sentences on the basis of
observation predicates.

Even in this generalized version, however, our criterion of cog-
nitive meaning may not do justice to advanced scientific theories,
wfiich are formulated in terms of “theoretical constructs,” such as
the terms “absolute temperature,” “gravitational potential,” “electric
field,” function,” etc. There are reasons to tiiink that neither
definitions nor reduction sentences are adequate to introduce these
terms on the basis of observ^ation predicates. Thus, e.g., if a system
of reduction sentences for the concept of electric field were avail-
able, then — to oversimplify the point a little — it would be possible
to describe, in terms of observable characteristics, some necessary^
and some sufficient conditions for the presence, in a given region,
of an electric field of any mathematical description, how^ever com-
plex. Actually, however, such criteria can at best be given only for
some sufficiently simple kinds of fields.

Now' theories of the advanced type here referred to may be
considered as hypothetico-deductive systems in which ail statements
are logical consequences of a set of fundamental assumptions. Fun-
damental as well as derived statements in such a system are formu-
lated either in terms of certain theoretical constructs which are not
defined within the system and thus play the role of primitives, or
in terms of expressions defined by means of the latter. Thus, in
their logical structure such systems equal the axiomatized uninter-
preted systems studied in mathematics and logic. They acquire
applicability to empirical subject matter, and thus the status of
theories of empirical science, by virtue of an empirical interpretation.
The latter is effected by a translation of some of the sentences of

[ 122 ] CAKL G. HEMPEL

the theory — often derived rather than fimdamental ones — into an
empiricist language, which may contain both observation predicates
and empirical constructs. And since the sentences which are thus
given empirical meaning are logical consequences of the fundamental
hypotheses of the theory, that translation effects, indirectly, a partial
interpretation of the latter and of the constructs in terms of which
they are formulated.^^

In order to make translatability into an empiricist language an
adequate criterion of cognitive import, we broaden therefore the
concept of empiricist language so as to include thing-languages in
the narrower and in the wider sense as well as all interpreted theo-
retical systems of the kind just referred to.^^ With this understanding,
(3.1) may finally serve as a general criterion of cognitive meaning.

5. On “the Meaning” of an Empirical Statement

In effect, the criterion thus arrived at qualifies a sentence as
cognitively meaningful if its nondogical constituents refer, directly
or in certain specified indirect ways, to observables. But it does not
make any pronouncement on what “the meaning” of a cognitively
significant sentence is, and in particular it neither says nor implies
that that meaning can be exhaustively characterized by what the
totality of possible tests would reveal in terms of observable phe-
nomena. Indeed, the content of a statement with empirical import
cannot, in general, be exhaustively expressed by means of any class
of observation sentences.

For consider fiivSt, among the statements permitted by our cri-
terion, any purely existential hypothesis or any statement involving

19, The distinction between a formal deductive system and the empirical theory
resulting from it by an interpretation has been elaborated in detail by Reicbenbach
in his penetrating studies of the relations between pure and physical geometry'; cf.,
e. g., Reichenbach (25). The metliod by means of which a formal system is given
empirical content is characterized by Reichenbach as “coordinating definition” of
the primitives in the theory by means of specific empirical concepts. As is suggested
by our discussion of reduction and the interpretation of theoretical construcis, how-
ever, the process in question may have to be construed as a partial interpretation
of the non-logical terms of the system rather than as a complete definition of the
latter in terms of the concepts of a thing-language.

20. These systems have not been characterized here as fully and as precisely as
would be desirable. Indeed, the exact character of the empirical interpretation of
theoretical constructs and of the theories in which they function is in need of further
investigation. Some problems which arise in this connection — such as whether, or
in what sense, theoretical constructs may be said to denote — are obviously also of
considerable epistemological interest Some suggestions as to the interpretation of
theoretical constructs may be found in Carnap (8), section 24, and in Kaplan (17);
for an excellent discussion of the epistemological aspects of the problem, see
Feigl (13).

The Empiricist Criterion of Meaning [ 123 ]

mixed quantiication. As was pointed out earlier, under {2,2) {a) y
statements of these kinds entaU no observation sentences whatever;
hence their content cannot be expressed by means of a class of ob-
servation sentences.

And secondly, even most statements of purely universal form
(such as “All flamingoes are pink”) entail observation sentences
(such as “That thing is pink”) only when combined with suitable
other observation sentences (such as “That thing is a flamingo”).

This last remark can be generalized. The use of empirical hypoth-
eses for the prediction of observable phenomena requires, in practi-
cally all cases, the use of subsidiary empirical hypotheses.^^ Thus,
e.g., the hypothesis that the agent of tuberculosis is rod-shaped
does not by itself entail the consequence that upon looking at a
tubercular sputum specimen through a microscope, rod-like shapes
will be observed: a large number of subsidiary hypotheses, including
the theory of the microscope, have to be used as additional premises
in deducing that prediction.

Hence, what is sweepingly referred to as “the (cognitive) mean-
ing” of a given scientific hypothesis cannot be adequately character-
ized in terms of potential observational evidence alone, nor can it
be specified for the hypothesis taken in isolation. In order to under-
stand “the meaning” of a hypothesis within an empiricist language,
we have to know not merely what observation sentences it entails
alone or in conjunction with subsidiary hypotheses, but also what
other, non-observational, empirical sentences are entailed by it, what
sentences in the given language would confirm or disconfirm it, and
for what other hypotheses the given one would be confirmatory^ or
disconfirmatory. In other words, the cognitive meaning of a statement
in an empiricist language is reflected in the totality of its logical rela-
tionships to all other statements in that language and not to the ob-
servation sentences alone. In this sense, the statements of empirical
science have a surplus meaning over and above what can be ex-
pressed in terms of relevant observation sentences.^^

6. The Logical Status of the
Empiricist Criterion of Meaning

What kind of a sentence, it has often been asked, is the empiri-
cist meaning criterion itself? Plainly it is not an empirical hypothesis;

21. This point is cleady taken into consideration in Ayer’s criteria of cognitive
significance, which were discussed in section 2.

22. For a fuller discussion of the issues here involved cf. Feigl (13) and the
comments on Feigl’s position which will be published together with that article.

[ 1Z4J

1---* *4. • ■» , CARL G. HEMPEL

by its ow^sSidSd.^ iSdeSoTcISS?

what claim of soundness or vaUdity coul? p“if be^ mS

indicates

s'or-ri

Sf fa rsu^rTotti^Snt

gendered and even less with r controversies it has en-

present article, that the changes inT^’ illustrated in the

been determined by the obiective r>f content have always

adequate index of cotmitive imnnrf criterion a more

nates the character of thl em^- objective illumi-

.ended ,o proSTa -"““"S. K ie in-

sentence which makes an intPii' -w^ ^^P^ication of the idea of a
nnnedly vague, a"?? TJ" ” ™a idea is ad-

place it by a more orerkt- ^ . Philosophic explication to re-
precision we cannot demand of^rn difference of

plicandum.-’^ hU then !re
exphcation, as expresld in , 0 ^

meaning? specific criterion of cognitive

rather generally recS^nlze? as S’ m '^hich are

another large class 0 /” which this is^ ^ intelligible assertions, and
We shall have to demanTS af i "r
account these spheres of common ^ai

ist us say, denies cognitiv^moort tS’ “ ^^P^'cation which,
to generalizations expressed iif terms ^^‘^"Pttons of past events or
jected as inadequate As te ufj^ observables has to be re-

~-d.s5S.s~ '^5;ssro"5l

g"l”pLf HH'SSH'" Ts

or i“the “woild oot

in<^ m outline the explication of ih^ ®^P^Jcation in his article (9) which eram
f? The’ Frege RiSSl'

(30)_are outstkoding exaSnfe’s of defirdtion

«n of various aspects of logical ana^:rTefkp^l^?"crp.^^^^^^ ^

The Empiricist Criterion of Meaning [ 125 |

But an adequate explication of the concept of cognitively sig-
nificant statement must satisfy yet another, even more important,
requirement: together with the explication of certain other concepts,
such as those of confirmation and of probability, it has to provide
the framework for a general theoretical account of the structure and
the foundations of scientific knowledge. Explication, as here under-
stood, is not a mere description of the accepted usages of the terms
under consideration: it has to go beyond the limitations, ambiguities,
and inconsistencies of common usage and has to show how we had
better construe the meanings of those terms if we wish to arrive at
a consistent and comprehensive theory of knowledge. This type of
consideration, which has been largely influenced by a study of the
structure of scientific theories, has prompted the more recent exten-
sions of the empiricist meaning criterion. These extensions are de-
signed to include in the realm of cognitive significance various types
of sentences which might occur in advanced scientific theories, or
which have to be admitted simply for the sake of systematic simplicity
and uniformity,-^ but on whose cognitive significance or non-signifi-
cance a study of what the term “intelligible assertion” means in
everyday discourse could hardly shed any light at all.

As a consequence, the empiricist criterion of meaning, like the
result of any other explication, represents a linguistic proposal which
itself is neither true nor false, but for which adequacy is claimed in
two respects: first in the sense that the explication provides a reason-
ably close analysis of the commonly accepted meaning of the ex-
piicandum — and this claim implies an empirical assertion; and sec-
ondly in the sense that the explication achieves a "'rational recon-
struction” of the explicandum, i.e., that it provides, together perhaps
with other explications, a general conceptual framework which per-
mits a consistent and precise restatement and theoretical systematiza-
tion of the contexts in which the explicandum is used — and this claim
implies at least an assertion of a logical character.

Though a proposal in form, the empiricist criterion of meaning
is therefore far from being an arbitrary definition; it is subject to
revision if a violation of the requirements of adequacy, or even a
way of satisfying those requirements more fully, should be discov-

25. Thus, e. g., our criterion qualifies as significant certain statements contain-
ing, say, thousands of existential or universal quantifiers — even though such sen-
tences may never occur in everyday nor perhaps even in scientific discourse. For
ind^d, from a systematic point of view it would be arbitrary and unjustifiabie to
limit the class of significant statements to those containing no more than some fixed
number of quantifiers. For further discussion of this point, cf. Carnap (6), sections
17, 24, 25.

[ 126 ]

^ j T j j • . CARL G, BDEMPEL

nrnhi ^ that before long some of the ooen

bibliographic references

Logic, Gollancz, London, 1936;

journal of Philos..

CofS’YoriT'iS" Macmillan

(4) “Operational Analysis” (Philos, of Science.

(6) cSSao R ’ ”T^ ®®"hn, 1928.

• a^nd

(7) Carnap, R., Logical Foundations of the Unitv of t

> "" wv.'rai"'

(9) Caman R ’ “Th^ science, I, 3, Umv. of Chicago Press, 1939.

LA i"r ?T9?5) °'

“““"'isfs,”- C„„di.i0.al-

vlTfiXTlT 52-^: “'■

Sof's? ■' l’g°“r‘;°Af ^ "“ 5“''“= M'ftol- (i>.9yc/,o/.

j PMd ;„ alaaw “A rsr'

?CX LAolA'S,?

(15) G»<ln.«.^N, rfe 5 ,„„„„ App„.. H.mri U.ive„ity

(16) Hempel, C. G., and Oppenheim P “Studip<! in tfiA • f t:

<.l‘l•ihs. of ScUnce, Vol’isf ms) ®’‘'

o/pmAvoAA™)”"" “f normal

(18) Wfort. C^H,^Re,i» i„ rfe , 00 . 00 , p, Spmi. Lop,.. Vol. 6

The Empiricist Criterion of Meaning [ ]

(19) Lecomte du Noiiy, Human Destiny, New York, London, Toronto,

1947.

(20) Lewis, C. L, An Analysis of Knowledge and Valuation, Open
Court Pub!., La Salle, 111., 1946.

(21) Pap, A., Elements of Analytic Philosophy, The Macmillan Co.,
New York, 1949.

(22) Popper, K., Logik der Forschung, Springer, Vienna, 1935.

(23) Popper, K., The Open Society and Its Enemies, 2 vols., Routledge,
London, 1945.

(24) Popper, K., “A Note on Natural Laws and So-called ‘Contrary-to-
Fact Conditionals’ ” {Mind, VoL 58, 1949).

(25) Reichenbach, H., Philosophie der Raum-Zeit-Lehre, Berlin, 1928.

(26) Reichenbach, H., Elements of Symbolic Logic, The Macmillan Co.,
New York, 1947.

(27) Russell, B., Human Knowledge, Simon and Schuster, New York,

1948.

(28) Schiick, M., “Meaning and Verification” (Philos. Review, Vol. 45,
1936). (Also reprinted in Feigl and SeUars, Readings in Philo-
sophical Analysis, New York, 1949).

(29) Stace, W. T. “Positivism” (Mind, Vol. 53, 1944).

(30) Tarski, A., “The Semantic Conception of Truth and the Founda-
tions of Semantics” (Philos, and Phcnorn. Research, Vol. 4,
1944). (Also reprinted in Feigl and Sellars, Readings in Philo-
sophical Analysis, New York, 1949.)

(31) Werkmeister, W. H., The Basis and Structure of Knowledge,
Harper, New York and London, 1948.

(32) Whitehead, A. N., and Russell, B., Principia Mathemaiica, 3 vols.,
2nd ed., Cambridge, 1925-1927.

REMARKS BY THE AUTHOR (1958)

If I were to write a revised version of this article, I would qualify the
objections (2.1) (b) and (2.2) (b) against complete verihability or falsi-
fiabHity as criteria of empirical meaningfulness, or empirical significance.
The first of these objections argues that if a sentence S is empirically sig-
nificant under the verifiability criterion, then so is 5 v N, even when N
is cognitively meaningless in the sense of being (i) neither analytic nor
self-contradictory and (ii) devoid of empirical meaning in the sense of
the verifiability criterion; for whatever class of observation sentences com-
pletely verifies S also completely verifies SvN, since SyN is & logical
consequence of S, — But the rule underlying this latter assertion, i.e., the
rule that an alternation is logically implied by either of its components,
applies only if N, no less than S, is a statement, i.e. a sentence which is
either true or false; and if the verifiability criterion is taken to characterize
all sentences, other than the analytic and the self-contradictory ones,

CARL G. HElvfPEL

[128]

wMcli can significantly be said to be either true or false, then clearly N
cannot be significantly said to be either true or false and thus is no state-
ment at all; hence the inference from S to SvN falls. — ^The case against
objection (2.2) (b) is analogous.^ However, the latter objection still ap-
plies against the view of those who propound faisifiability as a criterion
which will separate off the statements of empirical science from those of
logic and mathematics and from those of metaphysics, without denying
truth or falsity to the latter. For then S.N qualifies as a significant scien-
tific statement if S does, even though be a purely metaphysical utter-
ance. The remaining arguments mentioned in section 2 of my article
seems to me fully sufficient, however, to disqualif}’ both complete veri-
fiability and complete faisifiability as criteria of cognitive significance.

I have more serious doubts concerning the idea of a transl at ability
criterion of the kind proposed in sections 3 and 4 of the article. For the
notion of translatability needed in this context is by no means fully clear,
and an attempt to explicate it faces considerable difficulties.- It seems
desirable, therefore, to do without that idea. In a sequeF to the anicle
here under consideration, I did just that and considered instead the pos-
sibility of characterizing cognitively significant sentences as being built
up, according to specified syntactical rules, from a given logical vocabu-
lary and from cognitively (better: empirically) significant terms; each
of the latter would have to be either an observational predicate or an
expression connected with a set of observational terms by sentences of
specified types, such as definitions or reduction sentences, wnich could
then be said to introduce the non-observational term in question.-^ There
remains the problem of specifying the types of sentences which are to
be permissible for this purpose. This issue, which is briefly examined in
section 4 of the present article, has been dealt with in much greater
detail in two more recent essays of mine.^

1. A criticism to this effect was put forth some years ago by students in a
graduate seminar of mine; recently, the same point was made explicitly and
forcefully by D. Rynin in his presideniiai address, “Vindication of

Proceedings and Addresses of The American Philosophical Asso-
ciation, Vol. 30 (1957), p. 45-67; cf. especially pp. 57-58.

2. Tnis has recently been pointed out veiy^ lucidly by I. SchefBer in “Prospects
of a Modest Empiricism,” The Review of Metaphysics, Vol 10, pp, 383-400, 602-
625 (1957); cf. especially sections 7-11.

3. C. G. Hempel, “The Concept of Cognitive Significance: A Reconsideration,”
Proc. Amer. Acad, of Arts and Sciences, Vol. 80, No. 1, pp. 61-77 (1951).

4. This procedure seems closely related in spirit to one recently suggested by
Scheffler (loc. cit., section 9), namely replacement of the irajosiatabiiity' condition
by the following criterion: S is cognitively significant if and only if it w a sentence
of some empiricist language.

5. “A Logical Appraisal of Operationism,” The Scientific Monthly, Vol. 79,
pp. 215-220 (1954), reprinted in Philipp Frank, ed., The Validation of Scientific
Theories, the Beacon Press, Boston, 1957. — “The Theoretician’s Dilemma,” in H.
Feigl, M. Scriven, and G. Maxwell, eds., Minnesota Studies in the Philosophy of
Science, Vol. IL University of Minnesota Press, 1958. For a critical discussion of
the issues raised in these articles, see especially R. Carnap, “The Methodoiogicai
Character of Theoretical Concepts,” in H. Feigl and M. Scriven, eds., Minnesota

The Empiricist Criterion of Meaning [ 129 ]

But BO matter how one might reasonably delimit the class of sen-
tences qualified to introduce empirically significant terms, this new ap-
proach seems to me to lead to the realization that cognitive significance
cannot well be construed as a characteristic of individual sentences,
but only of more or less comprehensive systems of sentences (corre-
sponding roughly to scientific theories). A closer study of this point
suggests strongly that, much like the analytic-synthetic distinction, the
idea of cognitive significance, with its suggestion of a sharp distinction
between significant and non-significant sentences or systems of such, has
lost its promise and fertility as an explicandum, and that it had better be
replaced by certain concepts which admit of differences in degree, such
as the formal simplicity of a system; its explanatory and predictive power;
and its degree of confirmation relative to available evidence.® The analy-
sis and theoretical reconstruction of these concepts seems to offer the
most promising way of advancing further the clarification of the issues
implicit in the idea of cognitive significance.

Studies in the Philosophy of Science, Vol. I. University of Minnesota Press, 1956;
and sections 12-19 of SchefSer’s article cited in note 28.

6. This point is developed in detail in my anicle cited in note 3.

6

The Old and the New Logic

BY RUDOLF CARNAP
(translated by ISAAC LEVi)

1. Logic as a Method of Philosophizing

The new series of this journal, which begins with this volume,
will be devoted to the development of a new, scientific method of
philosophizing. Perhaps this method can be briefly characterized as
consisting in the logical analysis of the statements and concepts of
empirical science. This description indicates the two most important
features that distinguish this method from the methods of traditional
philosophy. First, this type of philosophizing goes strictly hand in
hand vith empirical science. Thus, philosophy is no longer viewed
as a domain of knowledge in its own right, on a par with, or superior
to, the empirical sciences. Secondly, this description indicates the
part that philosophy plays in empirical science: it consists in the
clarification of the statements of empirical science; more specifically,
in the decomposition of statements into their parts (concepts), the
step by step reduction of concepts to more fundamental concepts
and of statements to more fundamental statements. This way of
setting the problem brings out the value of logic for philosophical
enquiries. Logic is no longer merely one philosophical discipline
among others, but we are able to say outright: Logic is the method
of philosophizing. Logic is understood here in the broadest sense.
It comprehends pure, formal logic and applied logic or the theory
of knowledge.

The desire to replace metaphysical concept-poetry by a rigorous,
scientific method of philosophizing would have remained a pious
hope if the system of traditional logic had been the only logic^ in-

This article, originally entitled “Die alte und die neue Logik,” appeared in the first
issue of Erkenntnis. Vol. I of Erkenntnis (1930-31) was at the same time Vol. IX of
Annalen der Philosophie (see Editor’s Introduction, p. 6 above).. It is published here
with the kind permission of Professor Camap.

[ 133 ]

[ 134 ]

, . RUDOLF CARNAP

' av^able. Traditional logic was totally incapable of satisfy

grists ns “iS

tadt,duSr.t'SS' there Meed a peat many

—g iantiSr/ =i.“BTStpn' SMS

raSSMeTtageMSM “M".*'!' «”™ed at a

SS Tdl " M'preSfSceMM'thS

SdtaSSf tierenntoed by the inadequacy o7its fomtal

the S?aSdSLS meSSSS h'™" “t'

Tf ’’““f

SeVSpSSSnTora"SS“ f"

at first envisnapH Th significant nature were not

S tie SoSaS „I thenw"? P“^f Phere have even now taken
vantaae f “S for “‘""cted even less ad-

easy .i™.d.°y S Sch theraoMch

vent the new lo"ic is strii'ino^ Tn ht^ generally, circum-

by mathematics'"fricrhtf>r,c ^ ^ formal garb demanded

SSSifHSSSSS

the old philosophy is to he " advMates — hes the point at which
inexorable Idment of the t’"^ ““S't- Before the

sense, wuMM^oIuMM °f MtCM *” ""t

Kr°a ?T,‘- MSyM

materially ^ Proyes itself to be not merely

and therefore meM£s."''‘“ ™»nnhle

2. The New Logic

last^enm^ FoUowIm ^on° decades of the

earlier contributions (De MorganM^iTooklstSMl,

The Old and the New Logic [ 135 ]

and Schroder made the first attempts at a new and comprehensive
reconstruction of logic. On the basis of this previous work, White-
head and Russell created the great basic work of the new logic, Frm-
cipia Mathematica (1910-1913). All further contributions to the
new logic depend upon this work. They attempt either to supplement
or revise it. (A few names may be mentioned here; the Gottingen
School: Hilbert, Ackermann, Bemays, Behmann, et al; the Warsaw
School: Lukasiewicz, Lesniewski, Chwistek, Tarski, et al; Wittgen-
stein and his associate Ramsey.)

The most important stimulus for the development of the new
logic lay in the need for a critical re-examination of the foundations
of mathematics. Mathematics, especially since the time of Leibniz
and Newton, had made enormous advances and acquired an abun-
dance of new knowledge. But the securing of the foundations had
not kept in step with the rapid growth of the edifice. Therefore, about
a centur}^ ago, a more vigorous effort began to be made to clarify
the fundamental concepts. This effort was successful in many in-
stances. Mathematicians succeeded in defining in a rigorous form
such important concepts as, for example, limit, derivative and com-
plex number. For a long time, these concepts had been fruitfully
applied in practice without having adequate definitions. We have
only the sure instincts of great mathematicians and not the clarity
of concepts to thank for the fact that the inadequacy of the concept
formation caused no mischief in mathematics.

Efforts at a clarification of fundamental concepts went forward
step by step. People were not satisfied with reducing the various
concepts of mathematical analysis to the fundamental concept of
number; they required that the concept of number should itself be
logically clarified. This inquirv^ into the logical foundations of arith-
meric with a logical analysis of number as its goal, called peremptorily
for a logical system which had the comprehensiveness and precision
to do the work demanded of it. Thus, these inquiries gave an es-
pecially strong impetus to the development of the new logic. Peano,
Frege, Whitehead, Russell and Hilbert were led to do their work
on logic primarily for this reason.

The necessity for a new reconstruction of logic became even
more pressing wfien certain contradictions (“antinomies”) were no-
ticed in the realm of mathematics which soon proved themselves to
be of a general, logical nature. These contradictions could be over-
come only by a fundamental reconstruction of logic.

In the following pages, some of the important characteristics of
the new logic will be stated. Above all, mention will be made of

[ I RUDOLF CARNAP

those traits which distinguish the new logic from the old and by
means of which the new logic has gained a special significance for
Ae whole of science. First we shall take a look at the symbolic garb
in which the new logic customarily appears. Then a few remarks
will be made about the enrichment in content which consists pri-
marily in taking account of relations instead of restricting oneself
to predicates. In addition, it will be briefly shown how the contra-
dictions to which we have just referred are overcome by the so-called
theory of types. After dealing with these points, which are significant
chiefly for logic itself, we shall examine the several points of general
scientific importance: the possibility of deriving mathematics from
logic; the explanation of the essentially tautological character of logi-
cal sentences, a point which is ver^^ important for philosophy; the
analysis of concepts by means of which science is rendered a unified
whole; and finally the elimination of metaphysics by logical analysis.

3. The Symbolic Method

When a reader looks at a treatise in modern logic, the first out-
ward feature that strikes him is the use of symbolic forms which
appear similar to those of mathematics. This symbolism was orisi-
naJy' constructed in imitation of mathematics. However, forms more
suitable for the special purposes oi logic were subsequently developed.

in^ mathematics, the advantage of the symbolic method of repre-
sentation over verbal language is obvious. Consider the sentence: “if
one number is multiplied by another, the result is the same as that
obtained by multiplying the second by the first.” It is evidently much
clearer and more convenient to say, “For any numbers x and y,
iT IS the case that x.y = y.x” or more briefly, using the logical sif’n
for universality, “(a, y).x.y=:y..x.” - - - -

_ By _ employing symbolism "in logic, inferences acquire a rigor
which IS otherwise unobtainable. Inferences are made by means^of
arithmetical operations on formulae analogous to calculations (hence
the designation “calculus,” “propositional calculus,” “functional cal-
culus”). To be sure, material considerations guide the course of
deduction, but they do not enter into the deduction itself. This
method guarantees that no unnoticed assumptions will slip into the
deduction, a thing which it is very difficult to avoid in a word-
language. Such deductive rigor is especiallv important in the axio-
matoation of any domain, e.g. geometry. The history of geometry
furmshes numerous examples of impure deductions, such as the vari-
ous attempts to derive the axiom of parallels from the other axioms

The Old and the New Logic [ ]

of Euclidean geometry. A sentence equivalent to the axiom of paral-
lels was always tacitly assumed and employed in these derivations.
Rigor and neatness is required in the constitution of concepts just as
much as in the derivation of sentences. With the methods of the new
logic, analysis has shown that many philosophical concepts do not
satisfy the higher standards of rigor; some have to be interpreted
differently and others have to be eliminated as meaningless. (See
Section 9 below\)

As will become clearer presently, the theory of knowledge, which
is after all nothing but applied logic, can no more dispense with
symbolic logic than physics can dispense with mathematics.

4. The Logic of Relations

The new logic is distinguished from the old not only by the
form in which it is presented but chieSy also by the increase of its
range. The most important new domains are the theor}^ of relational
sentences and the theory of sentential functions. Only the theory- of
relations will be (briefly) considered here.

The only form of statements (sentences) in the old logic was the
predicative form: "‘Socrates is a man/' "All (or some) Greeks are
men.” A predicate-concept or property is attributed to a subject-
concept. Leibniz had already put fonvard the demand that logic
should consider sentences of relational form. In a relational sentence
such as, for example, "a is greater than b,” a relation is attributed
to two or more objects, (or. as it might be put, to several subject-
concepts). Liebniz's idea of a theory of relations has been worked
out by the new logic. The old logic conceived relational sentences
as sentences of predicative form. However, many inferences involv-
ing relational sentences thereby become impossible. To be sure, one
can interpret the sentence “a is greater than b” in such a way that
the predicate "greater than b" is attributed to the subject a. But
the predicate then becomes a unity; one cannot extract b by any
rule of inference. Consequently, the sentence "b is smaller than a”
cannot be inferred from this sentence. In the new logic, this infer-
ence takes place in the following way: The relation “smaller than”
is defined as the “converse” of the relation “greater than.” The in-
ference in question then rests on the universal proposition: If a
relation holds between x and y, its converse holds between y and x.
A further example of a statement that cannot be proved in the old
logic: “Wherever there is a victor someone is vanquished.” In the

1 138 1

^ ■* RUDOLF CARNAP

new logic, this follows from the logical proposition: If a relation
has a referent, it also has a relatum.

Relational statements are especially indispensable for the mathe-
matical sciences. Let us consider as an example the geometrical
rancep^f the three-place relation “between” (on an open straight
ime) Tht geometrical axioms “If a lies between b and c, b does
not he between c and a” can be expressed only in the new logic.
According to the predicative view, in the first case we would have
?” between b and c” and “lying between c and

. If these are left unanalyzed, there is no way of showing how the
first is tramformed into the second. If one takes the objects b and
c out of the predicate, the statement “a lies between b and c” no
lonpr serves to characterize only one object, but three. It is therefore
a three-place relational statement.

“between” are of such a kind
that the order of their terms cannot be altered at wHI. The deter-

™ domain rests essentially on relations
of this kind. If among a class of persons it is known which of any

persons is thereby serially ordered. It

asc$DtiMs^^ n predicative

^nptions— namely, by attributing a definite measure as .a property

ih f ™ ^bat case it would again have to be assumed

that with respect to any two of these quantities, it was known which

instructed This shows the indispensability of the theory of fela-

"“nd orderings:

(number senes), geometry (point series), physics (all

sta« mainSsr“°‘'

Restnction to predicate-sentences has had disastrous effects on
objects outside logic. Perhaps Russell is right when he made t£s
logical failing responsible for certain metaphysical errors If everv
sentence attributes a predicate to a subject; there can after aS b^

Sn ^nd every state of affairs must con-

^t m the possession of a certam attribute by the Absolute. In the

^^taphysical theories about mysterious “sub-
stances could be traced to this mistake.

a ^ certain that this restriction has for

a long time been a senous drag upon physics-^.g., the idea that

rr philosoVcal sfnse. Above S!

coticpnf 7 ^k logical error is responsible for the

concept of absolute space. Because the fundamental form of a prop-

The Old and the New Logic [ ]

osition had to be predicative, it could only consist in the specification
of the position of a body. Since Leibniz had recognized the possi-
bility of relational sentences, he was able to arrive at a correct
conception of space: the elementaiy^ fact is not the position of a
body but its positional relations to other bodies. He upheld the view
on epistemological grounds: there is no way of determining the abso-
lute position of a body, but only its positional relations. His campaign
in favor of the relativistic view of space, as against the absolutistic
views of the followers of Newton, had as little success as his pro-
gram for logic.

Only after two hundred years were his ideas on both subjects
taken up and carried through: in logic with the theoiy’ of relations
(De Morgan 1858; Peirce 1870), in physics with the theor>^ of rela-
tivity (anticipator}^ ideas in Mach 1SS3; Einstein 1905).

5. The Logical Antinomies

Around the turn of the centur}', certain strange contradictions
(‘‘paradoxes”) appeared in the new mathematical discipline of set
theor}^ Closer investigation soon showed that these contradictions
were not specifically mathematical but were of a general logical
character, the so-called “logical antinomies." The new logic had not
yet developed to the point where it was able to overcome these
contradictions. This was a defect which it shared with the old logic,
and it provided a further motive for rebuilding the system of logic
from its foundations. Russell succeeded in eliminating the contra-
dictions by means of the “theoiy of upes.” The gulf betw'een the
new and the old logic thereby became sail wider. The old logic is
not only significantly poorer in content than the new. but, because
the contradictions are not removed from it, it no longer counts at all.
(Most logical textbooks are still unaware of this.)

Let us consider the simplest example of an antinomy (foD owing
Russell). A concept is to be called “predicable” if it is applicable to
itself. For example: The concept “abstract” is abstract. A concept
is to be called “impredicable” if it does not apply to itself. For
example: The concept “virtuous” is not virtuous. According to the
law of excluded middle, the concept “impredicable” is either predi-
cable or impredicable. Assume that it is predicable; then, according
to the definition of “predicable,” it can 1^ ascribed to itself and is,
therefore, impredicable. Assume that the concept “impredicable” is
impredicable; then the concept is ascribed to itself; consequently,
according to the definition of “predicabie,” it is predicabie. There-

RUDOLF CARNAP

[ 140 ]

fore, both assumptions are self-contradictory. There are many similar
antinomies.

The theory of types consists in the fact that all concepts, both
properties and relations, are classified according to “types.” For
simplicity’s sake, let us restrict ourselves to properties. A distinction
is made between “individuals,” i.e. objects which are not properties
(zero level); properties of individuals (first level); properties of
properties of individuals (second level) and so on. Let us take for
example bodies to be individuals; then “square” and “red” are prop-
erties of the first level; “spatial property” and “color” are properties
of the second level. The theory of types says: a property of the first
level can be attributed or denied only to individuals but cannot
apply to properties of the first or higher levels at all; a property of
the second level can be attributed or denied only to properties of
the first level but cannot apply to individuals or to properties of the
second or higher levels, and so on. For example: If a and b are
bodies, the sentences “a is square” and “b is red” are either true
or false but in either case meaningful. Further, the sentences “Square-
ness is a spatial property” and “Red is a color” are true. On the
other hand, the series of words “a is a spatial property,” “Square-
ness is red” and “Color is a spatial property” are neither true nor
false but meaningless. They are mere pseudo-sentences. Such pseudo-
sentences are avoided if a property of the nth level is" applied only
to concepts of the level n-1. A particularly important special case
follows from this: The assumption that a certain property belongs
or does not belong to itself can be neither true nor false, .but is
meaningless.

As one can easily see, if the rules of the theory of types are
obeyed, the above-mentioned antinomy of “impredicable” does not
arise. For the stated definitions of “predicable” and impredicable”
cannot be formulated. They are therefore meaningless. The remaining
antinomies which have not been referred to here can be eliminated
in a similar manner.

6. Mathematics as a Branch of Logic

As has been mentioned, the logical analysis of arithmetic is one of
the goals of the new logic. Frege had already come to the conclusion
that mathematics is to be considered a branch of logic. This view was
confirmed by Whitehead and Russell who carried through the con-
struction of the system of mathematics on the basis of logic. It was
shown that every mathematical concept can be derived from the
fundamental concepts of logic and that every mathematical sentence

The Old and the New Logic [

(insofar as it is valid in every conceivable domain of any size) can
be derived from the fundamental statements of logic.

The most important concepts of the new logic (they are in part
reducible to one another) are the following: 1. Negation: “not”;

2. the logical connectives for two sentences: “and,” “or,” “if — ^then”;

3. “every” (or “all”), “there is”; 4. “identical.” The possibHity of
deriving arithmetical concepts may be illustrated by a simple ex-
ample: the number two as a cardinal, i.e., as the number of a concept.
Definition: “The cardinal number of a concept f is nvo” is to mean
“There is an x and there is a y such that x is not identical with y, x
falls under f, y fails under f, and for every z it is the case that if z
falls under f, z is identical with x or with y.” We see that only the
logical concepts which have just been listed are employed in this
definition of “two”; this can be shown rigorously only in a symbolic
representation. All the natural numbers can be defined in a similar
manner. Furthermore, the positive and negative numbers, fractions,
real numbers, complex numbers, and finally even the concepts of
analysis — ^limit, convergence, derivative, integral, continuity, etc. —
can also be defined in this way.

Since every mathematical concept is derived from the funda-
mental concepts of logic, every mathematical sentence can be trans-
lated into a sentence about purely logical concepts; and this transla-
tion is then deducibie (under certain conditions, as has been
indicated) from the fundamental logical sentences. Let us take as
an example the arithmetical sentence Its translation into

a sentence of pure logic reads: “If a property f has the cardinal
number 1 and a property g has the cardinal number 1, and f and g
are mutually exclusive, and if the concept h is the union of f and g,
then h has the cardinal number 2.” This translation represents a
sentence from the logic of properties (theoiy of sentential functions)
which is derivable from the fundamental sentences of logic. In a
similar way, all the remaining sentences of arithmetic and analysis
(to the extent that they are universally valid in the widest sense)
are provable as sentences of logic.

7. The Tautological Character of Logic

On the basis of the new logic, the essential character of logical
sentences can be clearly recognized. This has become of the greatest
importance for the theory of mathematical knowledge as w'eli as for
the clarification of controversial philosophical questions.

The usual distinction in logic between fundamental and derived

RUDOLF CARNAP

[ ^<2 ]

sentences is arbitrary. It is immaterial whether a logical sentence is
derived from other sentences. Its validity can be recognized from its
form. This may be illustrated by a simple example.

With the aid of the logical connectives, one can construct other
sentences from two sentences “A” and '‘B”, e.g., “not-A,” “A or B,”
“A and B.” The truth of these compound sentences obviously does
not depend upon the meanings of the sentences “A” and “B” but
only upon their truth-values, i.e., upon whether they are true or
fal^. Now there are four combinations of truth-values for “A” and
“B,” namely, 1. “A” is true and “B” is true: TT, 2. TF, 3. FT, 4.
FF. The meaning of a logical connective is determined by the fact
that the sentences constructed with the help of this connective are
true in certain of the four possible cases and false in the others. For
example, the meaning of “or” (in the non-exclusive sense) is de-
termined by the stipulation that the sentence ‘'A or B’’ is true in
the first three cases and false in the fourth. Compound sentences
can be combined further to make new compound sentences. Let us
take as an example: “(tiot-A and not-B) or (A or B).” We can
now establish the truth-values in the four cases first for the con-
stituent sentences and then for the sentence as a whole. We thereby
in this example arrive at a remarkable result. ‘‘Not-A” is true only
in the third and fourth cases. “Not-B is tnie only in the second and
fourth cases. Consequently, “not-A and not-B’' is true only in the
fourth case.

A B

T

T

F

F

not-A

F

F

T

T

not-B

F

T

F

T

not-A

and

not-B

F

F

F

T

A or B

T

T

T

F

( not-A and
not-B) or
(A orB)

T

T

T

T

“A or B” is true in the first three cases. Therefore, the entire sentence
“(not-A and not-B) or (A or B)” is true in every case. Such a
formula, which depends neither on the meanings nor the truth-
values of the sentences occurring in it but is necessarily true, whether
its constituent sentences are true or false, is called a tautology. A
tautology is true in virtue of its mere form. It can be shown that aU
the sentences of logic and, hence, according to the view advocated
here, all the sentences of mathematics are tautologies.

If a compound sentence is communicated to us, e.g., “It is rain-

The Old and the New Logic [ 143 ]

ing here and now or it is snowing/’ we learn something about reality.
This is so because the sentence excludes certain of the relevant
states-of-affairs and leaves the remaining ones open. In our example,
there are four possibilities: 1. It is raining and snowing, 2. It is
raining and not snowing, 3. It is not raining but it is snowing, 4. It
is not raining and not snowing. The sentence excludes the fourth
possibility and leaves the first three open. If, on the other hand, we
are told a tautology, no possibility is excluded but they all remain
open. Consequently, we learn nothing about reality from the
tautology, e.g., “It is raining (here and now) or it is not raining.’’
Tautologies, therefore, are empt}*'. They say nothing; they have,
so-to-speak, zero-content. However, they need not be trivial on this
account. The above-mentioned tautology is trivial. On the other
hand, there are other sentences whose tautological character cannot
be recognized at first glance.

Since ail the sentences of logic are tautological and devoid of
content, we cannot draw inferences from them about what was
necessary or impossible in reality. Thus the attempt to base meta-
physics on pure logic which is chiefly characteristic of such a system
as Hegel’s, is shown to be unwarranted.

Mathematics, as a branch of logic, is also tautological. In the
Kantian terminology^: The sentences of mathematics are analytic.
They are not synthetic a priori. Apriorism is thereby deprived of its
strongest argument. Empiricism, the view that there is no synthetic
a priori knowledge, has always found the greatest difficulty in inter-
preting mathematics, a difficulty which Mill did not succeed in
overcoming. This difficulty is removed by the fact that mathematical
sentences are neither empirical nor synthetic a priori but analytic.

8. Unified Science

We distinguish applied logic ^ the logical analysis of the concepts
and sentences of the different branches of science, from pure logic
with its formal problems. Though up to now most of the work in the
new logic has dealt with formal subjects, it has also attained successful
results in this domain.

The analysis of the concepts of science has shown that all these
concepts, no matter whether they belong, according to the usual
classification, to the natural sciences, or to psychology or the social
sciences, go back to a common basis. They can be reduced to root
concepts which apply to the “given,” to the content of immediate

RUDOLF CARNAP

[ 144 ]

experience. To begin with, all concepts relating to one’s own ex-
perience, i.e. those which apply to the psychological events of the
knowing subject, can be traced back to the given. Ail physical con-
cepts can be reduced to concepts relating to one’s own experience,
for every physical event is in principle confirmable by means of
perceptions. All concepts relating to other minds, that is, those that
apply to the psychological processes of subjects other than oneself,
are constituted out of physical concepts. Finally the concepts of the
social sciences go back to concepts of the kinds just mentioned.
Thus, a genealogical tree of concepts results in which every concept
must in principle find its place according to the way it is derived
from other concepts and ultimately from the given. The constitution
theory, i.e. the theoiy^ of the construction of a system of all scientific
concepts on a common basis, shows further that in a corresponding
manner every statement of science can be retranslated into a state-
ment about the given (“methodological positivism”).

A second constitution system, which likewise includes all con-
cepts, has physical concepts for its basis, i.e., concepts which apply to
events in space and time. The concepts of psychology and the social
sciences are reduced to physical concepts according to the principle
of behaviorism (“methodological materialism”).

We speak of “methodological” positivism or materialism because
we are concerned here only with methods of deriving concepts,
while completely eliminating both the metaphysical thesis of positiv-
ism about the reality of the given and the metaphysical thesis of
materialism about the reality of the physical world. Consequently,
the positivist and materialist constitution systems do not contradict
one another. Both are correct and indispensable. The positivist
system corresponds to the epistemological viewpoint because it proves
the validity of knowledge by reduction to the given. The materialist
system corresponds to the view-point of the empirical sciences, for
in this system all concepts are reduced to the physical, to the only
domain which exhibits the complete rule of law and makes inter-
subjective knowledge possible.

Thus, with the aid of the new logic, logical analysis leads to a
unified science. There are not different sciences with fundamentally
different methods or different sources of knowledge, but only one
science. All knowledge finds its place in this science and, indeed, is
knowledge of basically the same kind; the appearance of fundamental
differences between the sciences are the deceptive result of our using
different sub-languages to express them.

The Old and the New Logic

[145]

9. The Elimination of Metaphysics

The tautological character of lo^c shows that all inference is
tautological. The conclusion always says the same as the premises
(or less), but in a different linguistic form. One fact can never be
inferred from another. (According to the usual view this does occur
in inductive inference, but this subject cannot be discussed here.)
From this follows the impossibility of any metaphysics which tries
to draw inferences from experience to something transcendent which
lies beyond experience and is not itself experiencable; e.g. the “thing
in itself” lying behind the things of experience, the “Absolute”
behind the totality of the relative, the “essence” and “meaning” of
events behind the events themselves. Since rigorous inference can
never lead from experience to the transcendent, metaphysical infer-
ences must leave out essential steps. The appearance of transcendence
stems from this. Concepts are introduced which are irreducible either
to the given or to the physical. They are therefore mere illusory
concepts which are to be rejected from the epistemological viewpoint
as well as from the scientific viewpoint. No matter how much they
are sanctified fay tradition and charged with feeling, they are mean-
ingless words.

With the aid of the rigorous methods of the new logic, we can
treat science to a thoroughgoing process of decontamination. Ever}’
sentence of science must be proved to be meaningful by logical
analysis. If it is discovered that the sentence in question is either a
tautology or a contradiction (negation of a tautology), the statement
belongs to the domain of logic including mathematics. Alternatively
the sentence has factual content, i.e., it is neither tautological nor
contradictor}^; it is then an empirical sentence. It is reducible to the
given and can, therefore, be discovered, in principle, to be either
true or false. The (true or false) sentences of the empirical sciences
are of this character. There are no questions which are in principle
unanswerable. There is no such thing as speculative philosophy, a
system of sentences with a special subject matter on a par with those
of the sciences. To pursue philosophy can only be to clarify the
concepts and sentences of science by logicai analysis. The instrument
for this is the new logic.

[146]

RUBOLF CARNAP

REMARKS BY THE AUTHOR (1957)

The position explained in sections 8 and 9 of the foregoing paper
was modified in the years following its publication in the following respect.
The reduction of scientific concepts to the concepts of either of the two
bases indicated (viz., to the given, i.e., sense-data, or to observable prop-
erti^ of physical thmgs) cannot generally be carried out in the form of
explicit definitions. Therefore scientific sentences are in general not
translatable into sentences of either of the two bases; the relation between
them is more complicated. Consequently a scientific sentence is not
simply decidable as true or as false; it can only be more or less confirmed
on the basis of given observations. Thus the earlier principle of verifia-
bility, jfirst pronounced by Wittgenstein, was replaced by the weaker
requirement of confirmability. The thesis of the unity of science re-
mained, however, intact in virtue of the common basis of confirmation
for all branches of empirical science. The modification here indicated was
explained in the article “Testability and Meaning” (1936-37). For the
later development of the conception of the nature of scientific concepts,
see the article “The Methodological Character of Theoretical Concepts”
(1956), in H. Feigl and M. Scriven eds., Minnesota Studies in the Phi-
losophy of Science, VoL I.

7

i

I

Logic, Mathematics and

Knowledge of Nature
BY HANS HAHN
(translated by ARTHUR PAP)

I

Even a cursory glance at the statements of physics shows that they
are obviously of a very diverse character. There are statements like
“if a stretched string is plucked, a tone is heard” or “if a ray of
sunlight is passed through a glass prism, then a colored band, inter-
spersed with dark lines, is visible on a screen placed behind the
prism,” which can be tested at any time by observation. We also find
statements like “the sun contains hydrogen.” “the satellite of Sirius
has a density of about 60 , 000 ,” “a hydrogen atom consists of a
positively charged nucleus around which a negatively charged electron
revolves,” which cannot by any means be tested by immediate
observation but which are made only on the basis of theoretical
considerations and likewise are testable only with the help of theoreti-
cal considerations. And thus we are confronted by the urgent ques-
tion; what is the relationship between observation and theory in
physics — and not just in physics, but in science generally. For there
is but one science, and wherever there is scientific investigation it
proceeds ultimately according to the same methods; only we see
everything with the greatest clarity in the case of physics, because it
is the most advanced, neatest, most scientific of all the sciences. And
in physics, indeed, the interaction of observation and theory is

This contribution comprises the first four sections of tlie pamphlet “Logik, Mathe-
matik und Naturerkennen,” published in Vienna in 1933 as the second volume of the
series entitled “Einheitswissenschaft.” It is reproduced here with the kind permission
of Mrs. Lilly Hahn, Gerold & Co., Vienna, and Professor Rudolf Carnap, the co-
editor of Einheitswissenschaft. The last two sections of Hahn’s pamphlet which
are omitted do not deal with the nature of logical or mathematical propositions.

[ 147 3

f 3 HANS HAHN

especially pronounced, even officially recognized by the institution
of special professorships for experimental physics and for theoretical
physics.

Now, presumably the usual conception is roughly speaking the
following: we have two sources of knowledge, by means of which
we comprehend “the world,” “the reality” in which we are “placed”-
experience, or observation on the one hand, and thinking on the
other. For example, one is engaged in experimental physics or in
theoretical physics according to one’s using the one or the other of
tiiese sources of knowledge in physics.

Now, in philosophy we find a time-honored controversy about
these two sources of knowledge: which parts of our knowledge
denye from observation, are “a posteriori,” and which derive from
nking, are a priori”? Is one of these sources of knowledge
superior to the others, and if so, which?

beginning philosophy has raised doubts about the
reliability of observation (indeed, these doubts are perhaps the
source of all philosophy). It is quite understandable that such doubts
arose, t ey spring from the belief that sense -perception is frequently
deceptive. At sunrise or at sunset the snow on distant mountains
appears red, but “in reality” it is surelv white! A stick which is
immersed m water appears crooked, but “in reality”^t is surely
straight If a man recedes from me, he appears smaller and smaUer
to me, but surely he does not change size “in reality”!

Now, although all the phenomena to which we have been refer-
ring have long since been accounted for by physical theories, so that
nobody any longer regards them as deceptions caused by sense-
perception, t e consequences which flow from this primitive, lon^-
discarded conception stiU exert a powerful influence. One says: if
o seryation is sometimes deceptive, perhaps it is always so! Perhaps
everything disclosed by the senses is mere illusion! Everybody knows
the phenomenon of dreams, and everybody knows how difficult it is at
whether a given experience was “real life” or “a mere
whatever we observe is merely a dream

can hi' hallucinations occur, and that they

an be so vivid that the subject cannot be dissuaded from taking his

' then, whatever we observe is only

evei^Srln^' through appropriately polished lenses,

verythmg appears distorted; who knows whether perhaps we do not

JrssS’ tlte world as it were through distorting

h reSNi^ rilf see everything distorted, different from what
It really is! This is one of the basic themes of the philosophy of Kant

Logic, Mathematics and Knowledge of Nature [ 149 ]

But let us return to antiquity. As we said, the ancients believed
that they were frequently deceived by observation. But nothing of
this kind ever happened in the case of thought: there were plenty of
delusions of sense, but no delusions of thought! And thus, as confi-
dence in observation got shaken, the belief may have arisen that
thinking is a method of knowledge which is absolutely superior to
observation, indeed the only reliable method of knowledge: observa-
tion discloses mere appearance, thought alone grasps true being.

This, “rationalistic,” doctrine that thinking is a source of knowl-
edge which surpasses observation, that it is indeed the only reliable
source of knowledge, has remained dominant from the climax of
Greek philosophy until modem times. I cannot even intimate what
peculiar fmits matured on the tree of such knowledge. At any rate,
they proved to have extraordinarily little nourishing value; and thus
the “empiricist” reaction, originating in England, slowly gained the
upper hand, supported by the tremendous success of modern natural
science — the philosophy which teaches that observation is superior
to thought, indeed is the only source of knowledge: nihil est in
intellectu, quod non prius fuerit in sejtsu; in English: “nothing is in
the intellect which was not previously in the senses.”

But at once this empiricism faces an apparently insuperable
dijSiculty: how is it to account for the real validity of logical and
mathematical statements? Observation discloses to me only the
transient, it does not reach beyond the observed; there is no bond
that would lead from one observed fact to another, that would compel
future observations to have the same result as those already made.
The laws of logic and mathematics, however, claim absolutely uni-
versal validity: that the door of my room is now closed, I know by
observation; next time I observe it it may be open. That heated
bodies expand, I know by observ'ation: yet the very next observation
may show that some heated body does not expand; but that two and
two make four, holds not only for the case in which I verify it by
counting I know with certainty that it holds always and everywhere.
Whatever I know by observation could be otherwise: the door of
my room might have been open now, I can easily imagine it; and
I can easily imagine that a body does not expand on being heated;
but two and two could not occasionally make five, I cannot imagine
in any way what it would be like for twice two to equal five.

The conclusion seems inevitable: since the propositions of logic
and mathematics have absolutely universal validity, are apodeictically
certain, since it must be as they say and cannot be otherwise, these
propositions cannot be derived from experience. In view of the tre-

^ j ^ . HANS HAHN

mendous importance of logic and mathematics in the system of our
toowledge, empincism therefore, seems to be irrevocably refuted
To be sure, m spite of all this the older empiricists have Lemoted
we^no^ h and mathematics upon experience. According to them
we believe Aat something must be this way and caLt £
otherwise simply because the relevant experience is so old 3

iSiS -S— ^

a sign of good luck, an occurrence which is not so very rare^ hnw

!hf Ts'“’ 3

uiis iramework. As re^aras the imitc t

knowledge, opinions diverge

Thus it is, for instance, disputed whether geometry is a priori
periencTAn^^^^

nl^ssitZs o tho„ I? K ^ as

thf>v h H tiy various philosophers — but always after

^ ^ probably a prevalent tendency among nhvsi-

St aTsi'tidr'r" ”‘1'“ “pSs S.

o bemg as wide and general as possible, and to acknowledge

Logic, Mathematics and Knowledge of Nature [ 151 ]

experience as the source of our knowledge of ever^hing that is
somehow concrete.

The usual conception, then, may be described roughly as fol-
lows: from experience we leam certain facts, which we formulate
as ‘laws of nature”; but since we grasp by means of thought the
most general lawful connections (of a logical and mathematical
character) that pervade reality, we can control nature on the basis
of facts disclosed by observation to a much larger extent than it
has actually been observed. For we know in addition that anything
which can be deduced from observed facts by application of logic
and mathematics must be found to exist. According to this view,
the experimental physicist provides knowledge of laws of nature by
direct observation. The theoretical physicist thereafter enlarges this
knowledge tremendously by thinking, in such a way that we are in
a position also to assert propositions about processes that occur far
from us in space and time and about processes which, on account
of their magnitude or minuteness, are not directly observable but
which are connected with what is directly observed by the most
general laws of being, grasped by thought, the laws of logic and
mathematics. This view seems to be strongly supported by numerous
discoveries that have been made with the help of theor}', like — ^to men-
tion just some of the best known — the calculation of the position
of the planet Neptune by Leverrier, the calculation of electric waves
by Maxwell, the calculation of the bending of light rays in the gravi-
tational field of the sun by Einstein and the calculation of the red-
shift in the solar spectrum, also by Einstein.

Nevertheless we are of the opinion that this view is entirel3»- un-
tenable. For on closer analysis it appears that the function of thought
is immeasurably more modest than the one ascribed to it by this
theory. The idea that thinking is an instrument for learning more
about the world than has been observed, for acquiring knowledge of
something that has absolute validity always and everywhere in the
world, an instrument for grasping general laws of ail being, seems
to us wholly mystical. Just how should it come to pass that we could
predict the necessary outcome of an observation before having made
it? Whence should our thinking derive an executive power, by which
it could compel an observation to have this rather than that result?
Why should that which compels our thoughts also compel the course
of nature? One would have to believe in some miraculous pre-estab-
lished harmony between the course of our thinking and the course
of nature, an idea which is highly mystical and ultimately theological.

There is no way out of this situation except a return to a purely

[ 152 ] HANS HAHN

empiricist standpoint, to the view that observation is the only source
of knowledge of facts: there is no <3 priori knowledge about matters
of fact, there is no "'materiaV" a priori. However, we shall have to
avoid the error committed by earlier empiricists, that of interpreting
the propositions of logic and mathematics as mere facts of experi-
ence. We must look out for a different interpretation of logic and
mathematics.

n

Let us begin with logic. The old conception of logic is approxi-
mately as follows: logic is the account of the most universal prop-
erties of things, the account of those properties which are common
to all things; just as ornithology is the science of birds, zoology’ the
science of all animals, biolog>- the science of ail living beings, so
logic is the science of all things, the science of being as such. If
this were the case, it would remain wholly unintelligible whence
logic derives its certainty. For we surely do not know all things.
We have not observed everything and hence we cannot know how
everything behaves.

Our thesis, on the contrary, asserts: logic does not by any means
treat of the totality of things, it does not treat of objects^ at all but
only of our way of speaking about objects; logic is first generated
by language. The certainty and universal validity, 0: better, the
irrefutability of a proposition of logic derives just from the fact that
it says nothing about objects of any kind.

Let us clarify the point by an example. I talk about a well-known
plant: I describe it, as is done in botanical reference books, in terms
of the number, color and form of its blossom leaves, its calyx leaves,
its stamina, the shape of its leaves, its stem, its root, etc., and I
make the stipulation: let us caU any plant of this kind “’snow rose,"
but let us also call it “helleborus niger.” Thereupon I can pro-
nounce with absolute certainty the universally vdid proposition:
‘"every snow rose is a helleborus niger.” It is certainly valid, always
and everywhere; it is not refutable by any sort of obsen^ation; but
it says nothing at all about facts. I learn nothing from it about the
plant in question, when it is in bloom, where it may be found,
whether it is common or rare. It tells me nothing about the plant;
it cannot be disconfirmed by any observation. This is the basis of
its certainty and universal validity. The statement merely expresses
a convention concerning the way we wish to talk about the plant
in question.

Logic, Mathematics and Knowledge of Nature [ I

Similar considerations apply to the principles of logic. Let ns
make the point with reference to the two most famous laws of logic:
the law of contradiction and the law of the excluded middle. Take,
for example, colored objects. We learn, by training as I am tempted
to say, to apply the designation ‘Ted’’ to some of these objects, and
we stipulate that the designation “not red” be applied to ail other
objects. On the basis of this stipulation we now can assert with ab-
solute certainty the proposition that there is no object to which
both the designation ‘Ted” and the designation “not red” is applied.
It is customary to formulate this briefly by saying that nothing is
both red and not red. This is the law of contradiction. And since
we have stipulated that the designation “red” is to be applied to
some objects and the designation “not red” to all other objects,
we can likewise pronounce with absolute certainty the proposition:
eveiy^thing is either designated as “red” or as “not red,” which it
is customary' to formulate briefly by saying that eveiyhhing is either
red or not red. This is the law of the excluded middle. These
two propositions, the law of contradiction and the law of the
excluded middle, say nothing at all about objects of any kind.
They do not tell me of any of them whether they are red or
not red, wdich color they have, or anything else. They merely
stipulate a method for applying the designations “red” and “not
red” to objects, i.e. they prescribe a method of speaking about things.
And their universal validity and certainty, their irrefutability, just
derives from the fact that they say nothing at all about objects.

The same is to be said of ail the other principles of logic. We
shall presently return to this point. But first let us insert another
consideration. We have previously maintained that there can be no
material a priori, i.e. no a priori knowledge about matters of fact.
For we cannot know the outcome of an observation before the
latter takes place. We have made clear to ourselves that no material
a priori is contained in the laws of contradiction and of excluded
middle, since they say nothing about facts. There are those, how-
ever, who would perhaps admit that the nature of the laws of logic
is as described, yet would insist that there is a material a priori
elsewhere, e.g. in the statement “nothing is both red and blue” (of
course what is meant is: at the same time and place) which is
alleged to express real a priori knowledge about the nature of
things. Even before having made any observation, they say, one
can predict with absolute certainty that it will not disclose a thing
which is both blue and red; and it is maintained that such a priori
knowledge is obtained by “eidetic insight” or an intuitive grasp of

[ 154 ] HANS HAHN

the essence of colors. If one desires to adhere to our thesis that
there is no kind of material a priori, one must somehow face state-
ments like "‘nothing is both blue and red.” I want to attempt this
in a few suggestive words, though they cannot by any means do
full justice to this problem which is not easy. It surely is correct
that we can say with complete certainty before having made any
observations: the latter will not show that a thing is both blue and
red — ^just as we can say with complete certainty that no observation
will yield the result that a thing is both red and not red, or that a
snow rose is not a helleborus niger. The first statement, however, is
not a case of a material a priori any more than the second and third.
Like the statements “every snow rose is a helleborus niger”: and
“nothing is both red and not red,” the statement “nothing is both
blue and red” says nothing at all about the nature of things; it
likewise refers only to our proposed manner of speaking about ob-
jects, of applying designations to them. Earlier we said: there are
some objects that we call “red,” every other object we call “not
red,” and from this we derive the laws of contradiction and excluded
middle. Now we say: some objects we call “red,” some other objects
we call “blue,” and other objects again we call “green,” etc. But if
it is in this way that we ascribe color designations to objects, then
we can say with certainty in advance: in this procedure no object
is designated both as “red” and as “blue,” or more briefly: no ob-
ject is both red and blue. The reason why we can say this with cer-
tainty is that we have regulated the ascription of color designations
to objects in just this way.

We see, then, that there are two totally different kinds of state-
ments: those which really say something about objects, and those
Vr^hich do not say an 5 rthing about objects but only stipulate rules for
speaking about objects. If I ask “what is the color of Miss Ema’s
new^ dress?” and get the answer “Miss Ema’s new dress is not both
red and blue (all over),” then no information about this dress has
been given to me at all. I have been made no wiser by it. But if I
get the answer “Miss Erna’s new dress is red,” then I have received
some genuine information about the dress.

Let us clarify this distinction in terms of one more example. A
statement which reaUy says something about the objects which it
mentions, is the following: “If you heat this piece of iron up to
800°, it will turn red, if you heat it up to 1300°, it will turn white.”
What makes the difference between this statement and the state-
ments cited above, which say nothing about facts? The application
of temperature designations to objects is independent of the appli-

Logic, Mathematics and Knowledge of Nature [ 155 ]

cation of color designations, whereas the color designations “red”
and “not red,” or “red” and “blue” are applied to objects in mutual
dependence. The statements “Miss Ema’s new dress is either red or
not red” and “Miss Ema’s new dress is not both red and blue”
merely express this dependence, hence make no assertion about that
dress, and are for that reason absolutely certain and irrefutable.
The above statement about the piece of iron, on the other hand,
relates independently given designations, and therefore really says
something about that piece of iron and is for just that reason not
certain nor irrefutable by observation.

The following example may make the difference between these
two kinds of statements particularly clear. If someone were to tell
me: “I raised the temperature of this piece of iron to 800° but
it did not turn red,” then I would test his assertion; the result of
the test may be that he was lying, or that he w^as the victim of an
illusion, but perhaps it would turn out that — contrary to my previous
beliefs — there are cases where a piece of iron heated to 800° does
not become red-hot, and in that case I would just change my opinion
about the reaction of iron to heating. But if someone tells me “I
raised the temperature of this piece of iron to 800°, and this made
it turn both red and not red” or “it became both red and white,”
then I w’ill certainly make no test whatever. Nor will I say “he has
told me a lie,” or “he has become the victim of an illusion” and
it is quite certain that I would not change my beliefs about the
reaction of iron to heating. The point is — it is best to express it in
language which any card player is familiar with — that the man has
revoked: he has violated the rules in accordance with which we
w'ant to speak, and ! shall refuse to speak with him any longer. It
is as though one attempted in a game of chess to move the bishop
orthogonally. In this case too, I would not make any tests, I would
not change my beliefs about the behavior of things, but I would re-
fuse to play chess with him any longer.

To sum up: we must distinguish two kinds of statements: those
w^hich say something about facts and those which merely express
the way in which the rules which govern the application of words
to facts depend upon each other. Let us call statements of the latter
kind tautologies: they say nothing about objects and are for this
very reason certain, universally valid, irrefutable by observation;
whereas the statements of the former kind are not certain and are
refutable by observation. The logical laws of contradiction and
of the excluded middle are tautologies, likewise, e.g., the statement
“nothing is both red and blue.”

HANS HAHN

[ i56 ].

And now we maintain that in the same way all the other laws of
logic are tautologies. Let ns, therefore, return to logic once more
in order to clarify the matter by an example. As we said, the desig-
nation “red’’ is applied to certain objects and the convention is
adopted of applying the designation “not red” to any other object.
It is this convention about the use of negation which is expressed
by the laws of contradiction and of the excluded middle. Now we
add the convention — still taking our examples from the domain of
colors — that any object which is called “red” is also to be called
“red or blue,” “blue or red,” “red or yellow,” “yellow or red,” etc.,
that every object which is called “blue,” is also called “blue or red,”
“red or blue,” “blue or yellow,” “yellow or blue,” etc., and so on.
On the basis of this convention, we can again assert with complete
certainty the proposition: “every red object is either red or blue.”
This is again a tautology. We do not speak about the objects, but
only about our manner of talking about them.

If once more we remind ourselves of the way in which the des-
ignations “red,” “not red,” “blue,” “red or blue,” etc. are applied
to objects, we can moreover assert with complete certainty and ir-
refutability: eveiything to which both designations “red or blue”
and “not red” are applied, is also designated as “blue”— which is
usually put more briefly: if a thing is red or blue and not red, then
it is blue. Which is again a tautology. No information about the
nature of things is contained in it, it only expresses the sense in
which the logical words “not” and “or” are used.

Thus we have arrived at something fundamental: our conven-
tions regarding the use of the words “not” and “or” is such that in
asserting the two propositions “object A is either red or blue” and
“object A is not red,” I have implicitly already asserted “object A
is blue.” This is the essence of so-called logical deduction. It is not.
then, in any way based on real connections between states of affairs,
which we apprehend in thought. On the contrary, it has nothing at
all to do with the nature of things, but derives from our manner of
speaking about things. A person who refused to recognize logical
deduction would not thereby manifest a different belief from mine
about the behavior of things, but he would refuse to speak about
things according to the same rules as I do. I could not convince
him, but I would have to refuse to speak with him any longer, just
as I should refuse to play chess with a partner who insisted on
moving the bishop orthogonally.

What logical deduction accomplishes, then, is this: it makes us

Logic, Mathematics and Knowledge of Nature [ ^^'7 ]

aware of all that we have implicitly asserted — on the basis of con-
ventions regarding the use of language — in asserting a system of
propositions, just as, in the above example, “object A is blue”
is implicitly asserted by the assertion of the two propositions “object
A is red or blue” and “object A is not red.”

In saying this we have already suggested the answer to the ques-
tion, v^hich naturally must have forced itself on the mind of every
reader who has followed our argument: if it is really the case that
the propositions of logic are tautologies, that they say nothing about
objects, what purpose does logic serve?

The logical propositions which were used as illustrations derived
from conventions about the use of the words “not” and “or” (and
it can be shovvm that the same holds for ail the propositions of so-
called propositional logic). Let us, then, first ask for what purpose
the words “not” and “or” are introduced into language. Presumably
the reason is that we are not omniscient. If I am asked about the
color of the dress worn by Miss Erna yesterday, I may not be able
to remember its color. I cannot say whether it was red or blue or
green; but perhaps I will be able to say at least “it was not yellow.”
Were I omniscient, I should know its color. There would be no need
to say “it was not yellow”: I could say “it was red.” Or again: my
daughter has written to me that she received a cocker-spaniel as a
present. As I have not seen it yet, I do not know its color; I cannot
say “it is black” nor “it is brown”; but I am able to say “it is black
or brown.” Were I omniscient, I could do without this “or” and
could say immediately “it is brown.”

Thus logical propositions, though being purely tautologous,
and logical deductions, though being nothing but tautological trans-
formations, have significance for us because we are not omniscient.
Our language is so constituted that in asserting such and such prop-
ositions we implicitly assert such and such other propositions — ^but
we do not see immediately all that we have implicitly asserted in this
manner. It is only logical deduction that makes us conscious of it.
I assert, e.g., the propositions “the flower which Mr. Smith wears
in his buttonhole, is either a rose or a carnation,” “if Mr. Smith
wears a carnation in his buttonhole, then it is white,” “the flower
which Mr, Smith wears in his buttonhole is not white.” Perhaps I
am not consciously aware that I have implicitly asserted also “the
flower which Mr. Smith wears in his buttonhole is a rose”; but logi-
cal deduction brings it to my consciousness. To be sure, this does
not mean that I know whether the flower which Mr. Smith wears

HANS HAHN

[ 158 ]

in Ms buttonhole really is a rose; if I notice that it is not a rose,
then I must not maintain my previous assertions — otherwise I sin
against the rules of speaking, I revoke.

Ill

If I have succeeded in clarifying somewhat the role of logic, I
may now be quite brief about the role of mathematics. The proposi-
tions of mathematics are of exactly the same kind as the propositions
of logic: they are tautologous, they say nothing at all about the ob-
jects we want to talk about, but concern only the manner in which
we want to speak of them. The reason why we can assert apodeicti-
caliy with universal validity the proposition: 2 + 3 = 5, why we
can say even before any observations have been made, and can say
it v/ith complete certainty, that it will not turn out that 2 + 3 = 7,
is that by “2 + 3” we mean the same as by “5” — ^just as we mean
the same by "‘helleborus niger” as by “snow rose.” For this reason
no botanical investigation, however subtle, could disclose that an
instance of the species “snow rose” is not a helleborus niger. We
become aware of meaning the same by “2 + 3” and by “5,” by
going back to the meanings of “2,” “3,” “5,” “+,” and making
tautological transformations until we just see that “2 + 3” means
the same as “5.” It is such successive tautological transformation
that is meant by “calculating”; the operations of addition and mul-
tiplication which are learnt in school are directives for such tauto-
logical transformation; every mathematical proof is a succession of
such tautological transformations. Their utility, again, is due to the
fact that, for example, we do not by any means see immediately that
we mean by “24 X 31” the same as by “744”; but if we calculate
the product “24 X 31,” then we transform it step by step, in such a
way that in each individual transformation we recognize that on
the basis of the conventions regarding the use of the signs involved
(in this case numerals and the signs “+” and “X”) what we mean
after the transformation is still the same as what we meant before it,
until finally we become consciously aware of meaning the same by
“744” as by “24 X 31.”

To be sure, the proof of the tautological character of mathematics
is not yet complete in all details. This is a difficult and arduous task;
yet we have no doubt that the belief in the tautological character
of mathematics is essentially correct.

There has been prolonged opposition to the interpretation of
mathematical statements as tautologies; Kant contested the tauto-

Logic t Mathematics and Knowledge of Nature [ 159 ]

logical character of mathematics emphatically, and the great mathe-
matician Henri Poincare, to whom we are greatly indebted also for
philosophical criticism, went so far as to argue that since mathematics
cannot possibly be a huge tautology, it must somewhere contain an
a priori principle. Indeed, at first glance it is difficult to believe
that the whole of mathematics, with its theorems that it cost such
labor to establish, with its results that so often surprise us, should
admit of being resolved into tautologies. But there is just one little
point which this argument overlooks: it overlooks the fact that we
are not omniscient. An omniscient being, indeed, would at once
know everything that is implicitly contained in the assertion of a few
propositions. It would know immediately that on the basis of the
conventions concerning the use of the numerals and the multiplica-
tion sign, “24 X 31” is synonymous with “744.” An omniscient
being has no need for logic and mathematics. We ourselves, how-
ever, first have to make ourselves conscious of this by successive
tautological transformations, and hence it may prove quite surprising
to us that in asserting a few propositions we have implicitly also as-
serted a proposition which seemingly is entirely difierent from them, or
that we do mean the same by two complexes of symbols which are ex-
ternally altogether different.

I\'

And now let us be clear what a world-wide difference there is
between our conception and the traditional — perhaps one may say:
piatonizing — conception, according to which the w'orld is made in
accordance with the laws of logic and mathematics (“God is peren-
nially doing mathematics”), and our thinking, a feeble reflection of
God’s omniscience, is an instrument given to us for comprehending
the eternal laws of the world. No! Our thinking cannot give insight
into any sort of reality. It cannot bring us information of any fact
in the world. It only refers to the maimer in which we speak about
the world. All it can do is to transform tautologically what has been
said. There is no possibility of piercing through the sensible world
disclosed by observation to a “world of true being”; any metaphysics
is impossible! Impossible, not because the task is too difficult for
our human thinking, but because it is meaningless, because every
attempt to do metaphysics is an attempt to speak in a way that con-
travenes the agreement as to how we wish to speak, comparable
to the attempt to capture the queen (in a game of chess) by means
of an orthogonal move of the bishop.

HANS HAHN

[ 160 ]

Let US return now to the problem which was onr point of
departure: what is the relationship between observation and theory
in physics? We said that the usual view was roughly this: experience
teaches us the validity of certain laws of nature, and since our think-
ing gives us insight into the most general laws of all being, we know
that likewise anything which is deducible from these laws of nature
by means of logical and mathematical reasoning must be found to
exist. We see now that this view is untenable; for thinking does not
grasp any sort of laws of being. Never and nowhere, then, can
thought supply us with knowledge about facts that goes beyond the
observed. But what, then, should we say about the discoveries made
by means of theory on which, as we pointed out, the usual view so
strongly relies for its support? Let us ask ourselves, e.g., what was
involved in the computation of the position of the planet I^eptune
by Leverrier! Newton noticed that the familiar motions, celestial as
well as terrestrial, can be well described in a unified way by the
assumption that between any two mass points a force of attraction is
exerted which is proportional to their masses and inversely propor-
tional to the square of their distance. And it is because this assump-
tion enables us to give a satisfactory description of the familiar
motions, that he made it, i.e. he asserted tentatively, as an hypothesis,
the law of gravitation: between any two mass points there is a force
of attraction which is proportional to their masses and inversely pro-
portional to the square of their distance. He could not pronounce
this law as a certainty, but only as an hypothesis. For nobody can
know that such is really the behavior of ever)^ pair of mass points —
nobody can observe all mass points. But having asserted the law of
gravitation, one has implicitly asserted many other propositions,
that is, all propositions which are deducible from the law of gravi-
tation (together with data immediately derivable from observation)
by calculation and logical inference. It is the task of theoretical
physicists and astronomers to make us conscious of everything we
implicitly assert along with the law of gravitation. And Leverrier's
calculations made people aware that the assertion of the law of
gravitation implies that at a definite time and definite place in the
heavens a hitherto unknown planet must be visible. People looked
and actually saw that new planet — ^the hypothesis of the law of gravi-
tation was confirmed. But it was not Leverrier’s calculation that
proved that this planet existed, but the looking, the observ^ation. This
observation could just as well have had a different result. It could just
as well have happened that nothing was visible at the computed
place in the heavens — in which case the law of gravitation would

Logic, Mathematics and Knowledge of Nature [ 161 ]

not have been confirmed and one would have begun to doubt
whether it is really a suitable hypothesis for the description of the
observable motions. Indeed, this is what actually happened later:
in asserting the law of gravitation, one implicitly asserts that at a
certain time the planet Mercury must be visible at a certain place
in the heavens. Whether it would actually be visible at that time at
that place, only observation could disclose; but observations showed
that it was not visible at exactly the required position in the heavens.
And what happened? They said: since in asserting the law of gravi-
tation we implicitly assert propositions which are not true, we can-
not maintain the hypothesis of the law of gravitation. Newton’s theory
of gravitation w^as replaced by Einstein’s.

It is not the case, then, that we know through experience that
certain laws of nature are valid, and — since by our thinking we
grasp the most general laws of all being — therefore also know that
v/hatever is deducible from these laws by reasoning must exist. On
the contrary, the situation is this: there is not a single law of nature
which we know^ to be valid; the laws of nature are hypotheses which
we assert tentatively. But in asserting such laws of nature we im-
plicitly assert also many other propositions, and it is the task of
thinking to make us conscious of the implicitly asserted propositions.
So long, now', as these implicitly asserted propositions, to the extent
that they are about the directly obseiwable, are confirmed by ob-
servation, these laws of nature are confirmed and we adhere to
them; but if these implicitly asserted propositions are not confirmed
by observation, then the laws of nature have not been confirmed and
are replaced by others.

8

Psychology in Physical Language
BY RUDOLF CARNAP
(translated by GEORGE SCHICK)

1. Introduction. Physical Language
AND Protocol Language

In wkat follows, we intend to explain and to establish the thesis
that every sentence of psychology may be formulated in physical
language. To express this in the material mode of speech: all sen-
tences of psychology describe physical occurrences, namely, the
physical behavior of humans and other animals. This is a sub-thesis
of the general thesis of physicalism to the effect that physical lan-
guage is a universal language, that is, a language into which every
sentence may be translated. The general thesis has been discussed
in an earlier article/ whose position shall here serve as our point
of departure. Let us first briefly review some of the conclusions of
the earlier study.

In meta-linguistic discussion we distinguish the customary ma-
terial mode of speech (e.g. “The sentences of this language speak of
this and that object.’') from the more correct formal mode of speech
(e.g. “The sentences of this language contain this and that word
and are constructed in this and that manner.”) In using the material
mode of speech we run the risk of introducing confusions and pseudo-
problems. If, because of its being more easily understood, we occa-
sionally do use it in what follows, we do so only as a paraphrase of
the formal mode of speech.

Of first importance for epistemological analyses are the protocol

This article was originally published in Volume III of Erkenntnis (1932/33). It is
reproduced here with the Idnd permission of Professor Carnap.

1. Carnap, “Die Physikalische Sprache als Universalsprache der Wissenschaft/^
Erkenntnis 11, 1931, pp. 432-465. [The English translation of this article by Max
Black was published as a monograph under the title “The Unity of Science”
(London: Kegan Paul, 1934).]

[ 165 3

RUDOLF CARNAP

[ 166 ]

language, in wMch the primitive protocol sentences (in the material
mode of speech: the sentences about the immediately given) of a
particular person are formulated, and the system language, in which
the sentences of the system of science are formulated. A person S
tests (verifies) a system-sentence by deducing from it sentences of
his own protocol language, and comparing these sentences with those
of his actual protocol. The possibility of such a deduction of proto-
col sentences constitutes the content of a sentence. E a sentence
permits no such deductions, it has no content, and is meaningless. If
the same sentences may be deduced from two sentences, the latter
two sentences have the same content. They say the same thing, and
may be translated into one another.

To every sentence of the system language there corresponds some
sentence of the physical language such that the two sentences are
inter-translatable. It is the purpose of this article to show that this
is the case for the sentences of psychology’'. Moreover, every sentence
of the protocol language of some specific person is inter-translatable
with some sentence of physical language, namely, with a sentence
about the physical state of the person in question. The various proto-
col languages thus become sub-languages of the physical language.
The physical language is universal and inter-subjective. This is the
thesis of physicalism.

If the physical language, on the grounds of its universality, were
adopted as the system language of science, all science would become
physics. Metaphysics would be discarded as meaningless. The .vari-
ous domains of science would become parts of unified science. In
the material mode of speech: there would, basically, be only one
kind of object — physical occurrences, in whose realm law would
be all-encompassing.

Physicalism ought not to be understood as requiring psychology
to concern itself only with physically describable situations. Tlie
thesis, rather, is that psychology may deal with whatever it pleases,
it may formulate its sentences as it pleases — these sentences will, in
every case, be translatable into physical language.

We say of a sentence P that it is translatable (more precisely,
that it is reciprocally translatable) into a sentence Q if there are
rules, independent of space and time, in accordance with which Q
may be deduced from P and P from Q; to use the material mode
of speech, P and Q describe the same state of affairs; epistemologi-
cally speaking, every protocol sentence which confirms P also con-
firms Q and vice versa. The definition of an expression “a” by means
of expressions “b,” “c” . . . , represents a translation-rule with

Psychology in Physical Language [ ]

tlie Iieip of which any sentence in which “a” occurs may be trans-
lated into a sentence in which “a” does not occur, but “b/" ‘"c,” . . .
do, and vice versa. The translatability of all the sentences of language
Li into a (completely or partially) different language L2 is assured
if, for every expression of Li, a definition is presented which directly
or indirectly (i.e., with the help of other definitions) derives that
expression from expressions of L2. Our thesis thus states that a
definition may be constructed for every psychological concept (i.e.
expression) which directly or indirectly derives that concept from
physical concepts. We are not demanding that psychology formulate
each of its sentences in physical terminology. For its own purposes
psycholog}" may, as heretofore, utilize its own terminolog}". All that
we are demanding is the production of the definitions through which
psychological language is linked with physical language. We main-
tain that these definitions can be produced, since, implicitly, they
already underlie psychological practice.

If our thesis is correct, the generalized sentences of psycholog}",
the laws of psycholog}", are also translatable into the physical lan-
guage. They are thus physical laws. Whether or not these physical
laws are deducibie from those holding in inorganic physics, remains,
however, an open question. This question of the deducibility of the
laws is completely independent of the question of the definability of
concepts. We have already considered this matter in our discussion
of biology.- As soon as one realizes that the sentences of psychology
belong to the physical language, and also overcomes the emotional
obstacles to the acceptance of this provable thesis, one will, indeed,
incline to the conjecture, which cannot as yet be proved, that the
laws of psychology are special cases of physical laws holding in in-
organic physics as well But v/e are not concerned with this conjecture
here.

Let us permit ourselves a brief remark — apart from our principal
point^ — concerning the emotional resistance to the thesis of physical-
ism. Such resistance is always exerted against any thesis when an
Idol is being dethroned by it, when we are asked to discard an idea
with which dignity and grandeur are associated. As a result of
Copernicus’ work, man lost the distinction of a central position in
the universe; as a result of Darwin’s, he was deprived of the dignity
of a special supra-animal existence; as a result of Marx’s, the factors
by means of which history can be causally explained were degraded
from the realm of ideas to that of material events; as a result of

2. “Die Piiysikalische Sprache,” op. cit., p. 449 ff., {The Unity of Science,
p. 68 ff.).

[ 168 ]

XT- ♦ l, > • . RUDOLF CARNAP

of men can te causaUy explained were located in afSrlSt tote

StSaLT^f tSXoS: Lr ■

Se:;"^“= aVrri?' r

express the request SThe^rSlTSe rstdalldoT^ S'"'”"

to retain the objectivity and openness of minri t ^
the testing of a scientific thesis

2. The FoR^^s of Psychological Sentences

^ The distinction betv/een singular and general sentences is as

mponant in psycholog>.- as in other sciences. A s/ZZ pJcAo
logical sentence, e.g. “Mr A was ann,-,, a» ^‘nguiar psycno-

anaiogue of the physical sentence, “YeSday at°noorfhe^^”

with ? 28 de.;::fct^i^aJ^^^^^^

r -I'hir r cS “f ■ ~ A -Id

* scc;„d LpoS “t Z of„„VSletSoL1"?e'
nicats concerning sequences of events, that is. of causal laws Fo:
lu ^unce \^ nen, unaer such and such circumstances ima<T»s of

Stch -'„d “ M'- A oi: ,0 anyone

always (or- frequentiv^''^(?^’ emotion of such and such a sort

analogy Lid “wL a somTiIT^I “ ^ Pty^eal

Resi“arrh is ' ■ heated, it usually expands ”

t.n.? mK ^ primarily directed to the discovery of general sen

^yp-

P or on the basis of some smgle illustrative case. In our

Psychology in Physical Language [ 169 ]

view, knowledge cannot be gained by such means. We need not,
however, enter upon a discussion of this issue here, since even on
the view of phenomenology itself, these sentences do not belong to
the domain of psychology.

In physics it sometimes seems to be the case that a general law
is established on the basis of some single event. For instance, if a
physicist can determine a certain physical constant, say, the heat-
conductivity of a sample of some pure metal, in a single experiment,
he will be convinced that, on other occasions, not only the sample
examined but any similar sample of the same substance will, very
probably, be characterizable by the same constant. But here too in-
duction is applied. As a result of many previous observations the
physicist is in possession of a universal sentence of a higher order
which enables him in this case to follow an abbreviated method.
This higher-order sentence reads roughly: ‘‘All (or: the following)
physical constants of metals vary only slightly in time and from
sample to sample.”

The situation is analogous for certain conclusions drawn in
psychology'. If a psychologist has, as a result of some single experi-
ment, determined that the simultaneous sounding of two specific
notes is experienced as a dissonance by some specific person A, he
infers (under favorable circumstances) the truth of the general sen-
tence which states that the same experiment with A will, at other
times, have the same result. Indeed, he will even venture — and
rightly — to extend this result, with some probability, to pairs of
tones with the same acoustic interv'ai if the pitch is not too different
from that of the first experiment. liere too the inference from a
singular sentence to a general one is only apparent. Actually, a sen-
tence inductively obtained from many observations is brought into
service here, a sentence which, roughly, reads: “The reaction of
any specific person as to the consonance or dissonance of a chord
varies only very slightly with time, and only slightly on a not too
large transposition of the chord.” It thus remains the case that every^
general sentence is inductively established on the basis of a number
of singular ones.

Finally, we must consider sentences about psycho-physical inter-
relations, such as for instance, the connection between physical
stimulus and perception. These are likewise arrived at through in-
duction, in this case through induction in part from physical and in
part from psychological singular sentences. The most important sen-
tences of gestalt psychology belong also to this kind.

General sentences have the character of hypotheses in relation

I RUDOLF CARNAP

to concrete sentences, that is, the testing of a general sentence con-
sists in testing the concrete sentences which are deducible from it.
A general sentence has content insofar and only insofar as the con-
crete sentences deducible from it have content Logical analysis must
therefore primarily be directed towards the examination of the
latter sort of sentences.

If A utters a singular psychological sentence such as “Yesterday
mormng B was happy,” the epistemological situation differs accord-
mg as A and B are or are not the same person. Consequently, we
distinguish between sentences about other minds and sentences about
one^s own mind. As we shaU presently see, this distinction cannot
be made among the sentences of inter-subjective science. For the
epistemological analysis of subjective, singular sentences it is, how-
ever, mdispensable,

3. Sentences about Other Minds

, The epistemological character of a singular sentence about other
minds will now be clarified by means of an analogy with a sentence
about a physical property, defined as a disposition to behave (or
respond) in a specific manner under specific circumstances (or
stimuli). To take an example: a substance is called “plastic” if,
under the influence of deforming stresses of a specific sort and a
specific magnitude, it undergoes a permanent change of shape, but
remains intact.

We shall tr}’’ to carr}^ out this analog}’’ by juxtaposing two ex-
amples. We shall be concerned with the epistemological situation of
the example taken from psycholog}”; the parallel example about the
physical property is intended only to facilitate our understanding
of the psychological sentence, and not to serve as a specimen of an
argument from analogy. (For the sake of convenience, where the
text would have been the same in both columns, it is written only
once.)

A Sentence about a property of a A Sentence about a condition of
physical substance. some other mind.

E^ple: I assert the sentence P^: Example: I assert the sentence P.:
liais wooden support is very firm.” “Mr. A is now excited.”

There are two different ways in which sentence Pi may be derived.
We shall designate them as the “rational” and the “intuitive” meth-
ods. The rational method consists of inferring Pi from some protocol

Psychology in Physical Language [ ]

sentence pi (or from several like it), more specifically, from a
perception-sentence

about the shape and color of the
wooden support.

about the behavior of A, e.g. about
his facial expressions, his gestures,
etc., or about physical effects of A’s
behavior, e.g. about characteristics
of his handwriting.

In order to justify the conclusion, a major premise O is still re-
quired, namely the general sentence which asserts that

when I perceive a wooden support v/hen I perceive a person to have
to be of this color and form, it this facial expression and hand-
( usually) turns out to be firm. (A writing he (usually) turns out to
sentence about the perceptual signs be excited. (A sentence about the
of firmness.) expressional or graphological signs

of excitement.)

The content of Pi does not coincide with that of pi, but goes
beyond it. This is evident from the fact that to infer Pi from pi
O is required. The cited relationship between Pi and pi may also
be seen in the fact that under certain circumstances, the inference
from pi to Pi may go astray. It may happen that, though pi occurs
in a protocol, I am obliged, on the grounds of further protocols, to
retract the established system sentence Pi. I would then say some-
thing like, ‘T made a mistake. The test has shown

that the support was not firm, even that A was not excited, even though
though it had such and such a form his face had such and such an ex-
and color.” pression.”

In practical matters the intuitive method is applied more fre-
quently than this rational one, which presupposes theoretical knowl-
edge and requires reflection. In accordance with the intuitive method,
Pi is obtained without the mediation of any other sentence from
the identically sounding protocol sentence p2.

“The support is firm.” “A is excited.”

Consequently, one speaks in this case of immediate perceptions

properties of substances, e.g,, of other minds, e.g., of the excite-
of the firmness of supports. ment of A.

But in this case too the protocol sentence po and the system sentence
Pi have different contents. The difference is generally not noted
because, on the ordinary formulation, both sentences sound alike.

[ 172 ]

RUDOLF CARNAP

Here too we can best clarify the difference by considering the pos-
sibility of error. It may happen that, though p, occurs in my protocol,
I ^ obliged, on the basis of further protocols, to retract the estab-
lished system sentence Pj. I would then say “I made a mistake Fur-
ther tests have shown

that the support was not firm, al- that A was not excited, although I
?oX; “a?" 2" “

[The difference between p, and P, is the same as that between the

P 3tid Pi: “A red marble is lying
on this table of an earher example.^ The argument of that article
shows that the inference of P, from p„ if it il to be rigorous S
requires a major premise of general form, and that it is“ not in the

ordinary usage, for convenience's sake,
assigns to both sentences the same sequence of words, the inference
is, in practice, simplified to the point of trivialip'.]

Our problem now is: wfjat does sentence P, mean’’ Such a
question can only be answered by the presentation of a sentence (or
of several sentences) which has (or which conjointly have) the
same content as Pi. The viewpoint which will here be defended is
that Pi has the same content as a sentence P. which asserts the
existence of a physical structure characterized by the disposition to
react in a specific manner to specific physical stimuli. In our ex-
sSfcture^)' existence of that physical structure (micro-

of the wooden support that is char- of Mr. A's bodv tesneciaHv o? his

actenzed by the fact that, under a central nerv-ous sSemT that s

sight load, the support undergoes characterized bv a high tiulse and

no noticeable distortion, and, un- rate of breathing, whkh on the

fnd Sne^ bm "PPlication of certain stimuli, may

Seak ’ higher, by vehement

and factually unsatisfactorv’ answers
to cjuestions, by the occurrence of
agitated movements on the appii-
cation of certain stimuli, etc.

the eJ^nZirT’ ^ thoroughgoing analogy betw-een

the examples from physics and from psycholog\g If however we

were to qu estion the experts concerning" the examples Tom\rr

3. See Erkennlnis, Vol. 11, p. 460 (The Unity of Science, p. 92).

Psychology in Physical Language [ ]

respective jSeids, the majority of them nowadays would give us
thoroughly non-ahalogons answers. The identity of the content of Po

and of the content of the physical and of the content of the psycho-
sentence Pj would be agreed to as logical sentence would be denied
a matter of course by all physicists, by almost all psychologists (the

exceptions being the radical be-
haviorists) .

The contrary view which is most frequently advocated by psychol-
ogists is that, “A sentence of the form of Pi asserts the existence
of a state of affairs not identical with the corresponding physical
structure, but rather, only accompanied by it, or expressed by it.

In our example:

?! states that the support not only
has the physical structure described
by p2, but that, besides, there ex-
ists in it a certain force, namely its
firmness.

This firmness is not identical with
the physical structure, but stands
in some parallel relation to it in
such a manner that the firmness
exists when and only when a physi-
cal structure of the characterized
sort exists.

Because of this parallelism one may
consider the described reaction to
certain stimuli — ^wbich is causally
dependent upon that structure — ^to
be an expression of firmness.
Firmness is thus an occult prop-
erty, an obscure power which stands
behind physical structure, appears
in it, but itself remains unknow-
able.”

Pi states that Mr. A not only has
a body whose physical structure
(at the time in question) is de-
scribed by Po, but that — since he
is a psychophysical being — he has,
besides, a consciousness, a certain
power or entity, in which that ex-
citement is to be found.

This excitement cannot, conse-
quently, be identical with the cited
structure of the body, but stands
in some parallel relation (or in
some relation of interaction) to it
in such a manner that the excite-
ment exists when and only when
(or at least, frequently when) a
physical, bodily structure of the
characterized sort exists.

Because of this parallelism one may
consider the described reaction to
certain stimuli to be an expression
of excitement.

Excitement, or the consciousness
of which it is an attribute, is thus
an occult property, an obscure
power which stands behind physi-
cal structure, appears in it, but
itself remains unknowable.”

This view falls into the error of a hypostatization as a result of

[174 ] RUTOLF CARNAP

which a remarkable duplication occurs: besides or behind a state
of affairs whose existence is empirically determinable, another, paral-
lel entity is assumed, whose existence is not determinable. (Note
that we are here concerned with a sentence about other minds.)
Blit— one may now object — ^is there not really at least one possi-
bility of testing this claim, namely, by means of the protocol sentence
p2 about the intuitive impression of

the firmness of the support? the excitement of A?

The objector will point out that this sentence, after all, occurs in
the protocol along with the perception sentence pi. May not then a
system sentence whose content goes beyond that of P2 be founded
on p2? This may be answered as follows. A sentence says no more
than what is testable about it. If, now, the testing of Pi consisted in
the deduction of the protocol sentence p2, these two sentences would
have the same content. But we have already seen that this is im-
possible.

There is no other possibility of testing Pi except by means of
protocol sentences like pi or like po. If, now% the content of Pi
goes beyond that of P2, the component not shared by the two senr
tences is not testable, and is therefore meaningless. If one rejects
the interpretation of Pi in terms of P2, Pi becomes a metaphysical
pseudo-sentence.

The various sciences today have reached very different stages in
the process of their decontamination from metaphysics. Chiefly be-
cause of the efforts of Mach, Poincare, and Einstein, physics is. by
and large, practically free of metaphysics. In psychology;, on the
other hand, the work of arriving at a science which is to be free of
metaphysics has hardly begun. The difference betw^een the tw'o sci-
ences is most clearly seen in the different attitudes taken by experts
in the two fields towards the position which we rejected as meta-
physical and meaningless. In the case of the example from physics,
most physicists would reject the position as anthropomorphic, or
mythological, or metaphysical. They thereby reveal their anti-meta-
physical orientation, which corresponds to our own. On the other
hand, in the case of the example from psychology (though, perhaps,
not when it is so crudely formulated), most psychologists would
today consider the view we have been criticizing to be self-evident
on intuitive grounds. In this one can see the metaphysical orientation
of psychologists, to which ours is opposed.

Psychology in Physical Language

[175]

4. Rejoinder to Four Typical Criticisms

Generalizing the conclusion of the argument which, with refer-
ence to a special case, we have been pursuing above, we arrive at
the thesis that a singular sentence about other minds always has the
same content as some specific physical sentence. Phrasing the same
thesis in the material mode of speech — a sentence about other minds
states that the body of the person in question is in a physical state
of a certain sort. Let us now discuss several objections against this
thesis of physicalism.

A. Objection on the ground of the undeveloped state of physiol-
ogy: “Our current knowledge of physiology — especially our knowl-
edge of the physiology of the central nervous system — is not yet
sufficiently advanced to enable us to know to what class of physical
conditions something like excitement corresponds. Consequently,
when today we use the sentence 'A is excited,’ we cannot mean by
it the corresponding physical state of affairs.”

Rebuttal Sentence Pi, “A is excited” cannot, indeed, today be
translated into a physical sentence P3 of the form “such and such a
physico-chemical process is now taking place in A’s body” (expressed
by a specification of physical state-coordinates and by chemical
formulae). Our current knowledge of physiology is not adequate for
this purpose. Even today, however, Pi may be translated into another
sentence about the physical condition of A’s body, namely into
the sentence P2, to which we have already referred. This takes the
form “A’s body is now in a state which is characterized by the fact
that when I perceive A’s body the protocol sentence pi (stating my
perception of A’s behavior) and (or) the protocol sentence po
(stating my intuitive impression of A’s excitement) or other, analo-
gous, protocol sentences of such and such a sort are produced.” Just
as, in our example from physics, sentence Pi, “The wooden support
is firm,” refers to the physical structure of the wooden support — and
this even though the person using the sentence may sometimes not
be capable of characterizing this physical structure by specifying the
distribution of the values of the physical state-coordinates, so also
does the psychological sentence Pi, “A is excited,” refer to the
physical structure of A’s body — ^though this structure can only be
characterized by potential perceptions, impressions, dispositions to
react in a specific maimer, etc., and not by any specification of state-
coordinates. Our ignorance of physiology can therefore affect only
the mode of our characterization of the physical state of affairs in

[ 176 ] RUDOLF CARNAP

qiiestioH. It in no way touches upon the principal point: that sen-
tence Pi refers to a physical state of affairs.

B, Objection on the ground of analogy: ‘"When I myself am
angry, I not only act out the behavior-pattern of an angry man, I
experience a special feeling of anger. If, consequently, I observe
someone else acting out the same behavior-pattern I may, on grounds
of analogy, conclude (if not with certainty, at least with probability)
that he too, besides acting as he does, now has a feeling of anger
(which is not meant as a physical state of affairs).”

Rebuttal, Though arguments from analogy are not certain, as
probability arguments they are undoubtedly admissible. By way of
an example let us consider an every-day argument from anaiog}^ I
see a box of a certain shape, size, and color. I discover that it con-
tains matches. I find another box of a similar appearance, and now,
by analogy, draw the probability inference that it too contains
matches. Our critic believes that the argument from analogy he
presents is of the same logical form as the argument just presented.
If this were the case, his conclusion would certainly be sound. But
this is not the case. In our critic’s argument, the conclusion is mean-
ingless — a mere pseudo-sentence. For, being a sentence about other
minds, not to be physically interpreted, it is in principle ndt testable:
This w'as the result of our previous considerations; objection D will
offer us an opportunity for discussing it again. In the non-testability
of our critic’s conclusion rests also the difference between his argu-
ments and the example just cited. That the second box also con-
tains matches may in principle be tested and confirmed by observa-
tion sentences of one’s protocol. The two analogous sentences, “The
first box contains matches” and “The second box contains matches”
are both logically and epistemologically of the same sort. This is why
the analogy holds here. The case is different with “I am angry” and
“That person is angry.” We consider the former of these two sen-
tences to be meaningful and the latter (if its physical interpretation
is rejected) to be meaningless. Our critic, who considers the latter
as well as the former sentence to be meaningful, will believe that
the person who asserts the sentence finds it testable, only in a manner
altogether different from that in which the former is testable. Thus
both of us agree that the latter sentence is epistemologically dif-
ferent from the former. The use of the same grammatical structure
in these two sentences is logically illegitimate. It misleads us into
believing that the two sentences are of the same logical form, and
that one may be used as an analogue of the other.

If the conclusion is acknowledged to be meaningless, it remains

Psychology in Physical Language [ ]

to be explained how this pseudo-sentence was introduced into the
argument. The logical analysis of concept formation and of sentences
in science and (especially) in philosophy very frequently discloses
pseudo-sentences. However, a pseudo-sentence rarely turns up as
the conclusion of an argument from analogy with meaningful prem-
ises. This may readily be accounted for. An argument from analogy
has (in a simple case) the following form. Premises: If A has the
property E, it always also has the property F; A^ resembles A in
many respects; A' has the property E. We conclude (with proba-
bility) : A' also has the property F. Now, according to semantics, if
“A” and “B” are object-names, “E” and “F” property-names, and
‘‘E(A)'’ means that A has the property E, then a) if “E(A)’' and
‘‘E(B)'' are meaningful (i.e. either true or false), “A” and “B”
belong to the same semantic ty^'pe; b) if two names, “A” and “B/’
belong to the same semantic type, and ‘T(A)” is meaningful, then
“F(B)'’ is also meaningful. In the case under discussion here “E(A)”
and “E(Aty” are meaningful, and consequently — in accordance with
b) — “F(AO/’ the conclusion of the argument from analogy, is also
meaningful. Thus if the premises of an argument from, analogy are
meaningful and yet the conclusion is meaningless, the formulation
of the premises must be in some way logically objectionable. And
this is indeed the case with the argument from analogy presented
by our critic. The predicative expression ‘1 am angry” does not
adequately represent the state of affairs which is meant. It asserts
that a certain property belongs to a certain entity. All that exists,
however, is an experienced feeling of anger. This should have been
formulated as, roughly, ‘'now anger.” On this correct formulation
the possibility of an argument from analogy disappears. For now
the premises read: when I (i.e. my body) display angry behavior,
anger occurs; the body of another person resembles mine in many
respects; the body of the other person is now displaying angry
behavior. The original conclusion can now no longer be drawn,
since the sentence “Anger occurs” contains no “I” which may be
replaced by “the other person.” If one wanted to draw the appro-
priate conclusion, in which no substitution is made but the form of
the premises simply retained, one would arrive at the meaningful but
plairily false conclusion, “Anger occurs” — ^which states what would
be expressed in ordinary language by “I am now angry.”

C. Objection on the ground of mental telepathy, “The telepathic
transmission of the contents of consciousness (ideas, emotions,
thoughts) occurs without any determinable physical mediation. Here
we have an instance of the knowledge of other minds which involves

.5 f

fl

- %

[ 178 ] RUDOLF CARNAP

no perception of other people’s bodies. Let ns consider an example.
I wake up suddenly one night, have a distinct sensation of fear, and
know that my friend is now experiencing fear; later, I discover that
at that very moment my friend was in danger of death. In this case,
my knowledge of my friend’s fear : cannot refer to any state of his
body, for I know nothing of that; my knowledge concerns itself im-
mediately with my friend’s sensation of fear.”

Rebuttal, Psychologists are not yet unanimously decided on the
degree to which they ought properly to credit the occurrence of
cases of telepathy. This is an empirical problem which it is not our
business to solve here. Let us concede the point to our critic, and
assume that the occurrence of cases of telepathic transmission has
been confirmed. We shall show that, even so, our earlier contentions
are not affected in the least. The question before us is: what does
sentence Pi, “My friend now experiences fear” mean, if I take Pi
to be a statement of telepathically derived cognition? We maintain
that the meaning of Pi is precisely the same as it would be if we
used it on the grounds of some normally (rationally or intuitively)
derived cognition. The occurrence of telepathy in no way alters the
meaning of Pi.

Let us consider a precisely analogous situation involving the cog-
nition of some physical event. I suddenly have the impression that
a picture has fallen from the wall at my house, and this when neither
I nor anyone else can in any normal way perceive that this has
happened. Later, I discover that the picture has, indeed, fallen from
the wall. I now express this cognition which I have obtained by
clairvoyance in sentence Q, “The picture has now fallen from the
wall.” What is the meaning of this sentence? The meaning of Q
here is clearly the same as it would be if I used it on the ground of
some normally derived cognition, that is, on the ground of some
cognition by direct perception of the event in question. For in both
cases Q asserts that a physical event of a certain sort, a specific dis-
placement of a specific body, has taken place.

The case is the same with telepathic cognition. We have already
considered the case in which the state of some other mind is intui-
tively grasped, though by means of a perception of the other person’s
body. If a telepathic cognition of the state of some other mind
occurs, it too is based on an intuitive impression, this time without
a simultaneous perception. That which is cognized, however, is the
same in both cases. Earlier, we remarked that Pi does not have the
same content as the protocol sentence p2 about the (normally) intui-
tive impression, and that cannot support a sentence about some-

Psychology in Physical Language [ 179 ]

tiling beside or behind the physical condition of the other person’s
body. Our remarks hold equally for telepathically intuitive im-
pressions.

D. Objection on the ground of statements by others, “We are, to
• begin with, agreed that A is in a certain physical state which is mani-

fested fay behavior of a certain sort and produces in me, apart from
sense-perceptions, an intuitive impression of A’s anger. Beyond this,
however, I can find out that A really does experience anger by
questioning him. He himself wHl testify that he experienced anger.
Knowing him to be a truthful person and a good observer, why
should I not consider his statement to be true — or at least probably
I true?”

i Rebuttal Before I can decide w^hether I should accept A’s state-

j ment as true, or false, or probably true — before, indeed, I can con-

sider this question at all — I must first of all understand the statement.
It must have meaning for me. And this is the case only if I can
test it, if, that is, sentences of my protocol are deducible from it.
If the expression is interpreted physically it is testable by means of
protocol sentences such as my pi and po, that is, by sentences about
specific perceptions and intuitive expressions. Since, however, our
critic rejects the physical interpretation of the expression, it is in
principle impossible for me to test it. Thus it is meaningless for me,
and the question whether I should consider it to be true, or false,
or probable, cannot even be posed.

Should unusual, brilliant patterns suddenly appear in the sky —
even if they took the form of letters which seemed to compose a
j sentence — science could not comprehend them except by first con-

5 cehing them, describing them, and explaining them (i.e. subsuming

j them under general causal-sentences) as physical facts. The question

w'hether such an arrangement of symbols constitutes a meaningful
sentence must be decided without taking into consideration whether
or not it appears in the sky. K this symbol-arrangement is not a
meaningful sentence at other times, it cannot become one no matter
: how effulgent an appearance it makes in the sky. Whether a sen-

I tence is true or false is determined by empirical contingencies; but

whether a sentence is or is not meaningful is determined solely by
the syntax of language.

It is no different in the case of those acoustic phenomena that
issue from the mouths of certain vertebrates. They are first of all
facts, physical occurrences, and specifically, sound waves of a cer-
tain sort. We can, further, also interpret them as symbols. But
whether or not such an arrangement of symbols is meaningful can-

[ 180 I EUDOLF CARNAP

not depend on its occurrence as an acoustic phenomenon. If the
sentence “A was angry yesterday at noon” has no meaning for me
— as would be the case if (insofar as our critic rejects its physical
meaning) I could not test it — it will not be rendered meaningful by
the fact that a sound having the structure of this sentence came from
A’s own mouth.

But — it will be asked — do we not need the statements of our
fellow-men for the elaboration of inter-subjective science? Would not
physics, geography, and history become very meager studies if I
had to restrict myself in them to occurrences which I myself had
directly observed? There is no denying that they would. But there
is a basic difference between a statement by A about the geography
of China or about some historical event in the past on the one
hand, and, on the other, a statement by A about the anger he felt
yesterday. I can, in principle, test the statements of the first sort
by means of perception sentences of my own protocol, sentences
about my own perceptions of China, or of some map, or of historical
documents. It is, however, in principle impossible for me to test
the statement about anger if our critic asks me to reject the physical
meaning of the sentence. If I have often had occasion to note
that the geographical or historical reports that A makes can be con-”
firmed by me, then, on the basis of an inductive probability inference,
I consider myself justified in using his other statements — insofar as
they are meaningful to me — in the elaboration of my scientific knowl-
edge. It is in this way that inter-subjective science is developed. A
sentence, however, which is not testable and hence not meaningful
prior to its statement by A is not any the more meaningful after such
a statement. If, in accordance with our position, I construe A’s state-
ment about yesterday’s anger as a statement about the physical con-
dition of A’s body yesterday, this statement may be used for the
development of inter-subjective science. For we use A’s sentence as
evidence (just to the extent to which we have found A to be trust-
worthy) in support of the attribution of a corresponding physical
structure to the corresponding spatio-temporal region of our physical
world. Neither do the consequences which we draw from this attribu-
tion generically differ from those that are obtained from any other
physical statement. We build our expectations of future perceptions
on it — in this case with respect to A’s behavior, as in other cases
with respect to the behavior of other physical systems.

The assertions of our fellow men contribute a great deal to ex-
tending the range of our knowledge. But they cannot bring us any-
thing basically new, that is, anything which cannot also be learned

Psychology in Physical Language [ ]

in some other way. For the assertions of our fellow men are, at
bottom, no different from other physical events. Physical events are
different from one another as regards the extent to which they may
be used as signs of other physical events. Those physical events which
we call “assertions of our fellow man” rank particularly high on this
scale. It is for this reason that science, quite rightly, treats these
events with special consideration. However, between the contribution
of these assertions to our scientific knowledge and the contributions
of a barometer there is, basically, at most a difference of degree.

5. Behaviorism and “iNTUixrvT” Psychology

The position w^e are advocating here coincides in its broad out-
lines with the psychological movement knovn as “behaviorism” —
when, that is, its epistemological principles rather than its special
methods are considered. We have not linked our exposition with a
statement of behaviorism since our only concern is with epistemo-
logical foundations while behaviorism is above aU else interested
in a specific method of research and in specific concept formations.

The advocates of behaviorism were led to their position through
their concern with animal psychoiog>'. In this domain, w^hen the
material given to observation does not include statements but only
inarticulate behavior, it is most easy to arrive at the correct method
of approach. This approach leads one to the correct interpretation
of the statements of human experimental subjects, for it suggests
that these statements are to be conceived as acts of verba lizin g be-
havior, basically no different from other behavior.

Behaviorism is confronted with views, more influential in Ger-
many than in the United States, which uphold the thesis that psy-
chology’s concern is not with behavior in its physical aspect, but
rather, with meaningful behavior. For the comprehension of mean-
ingful behavior the special method known as “intuitive understand-
ing” (“Verstehen”) is said to be required. Physics aUegedly knows
nothing of this method. Neither meaningful behavior considered
collectively nor the individual instances of such behavior which
psychology investigates can possibly — so it is maintained — ^be char-
acterized in terms of physical concepts.

In intuitive psychology this view^ is generally linked with the view
that beside physical behavior there is yet another, psychical event,
which constitutes the true subject-matter of psychology, and to which
intuitive understanding leads. We do not want to consider this idea
any further here, since we have already thoroughly examined it.

RUDOLF CARNAP

[ 182 ]

But even after one puts this idea aside, intuitive psychology
poses the following objection to physicalism.

Objection based on the occurrence of ** meaningful behavior”
"‘When psychology considers the behavior of living creatures (we
disregard here the question whether it deals only with such behavior),
it is interested in it as meaningful behavior. This aspect of behavior
cannot, however, be grasped in terms of physical concepts, but only
by means of the method of intuitive understanding. And this is why
psychological sentences cannot be translated into physical sentences.”

Rebuttal. Let us recall a previous example of the physicalization
of an intuitive impression, i.e. of a qualitative designation in the
protocol language.^ We there showed that it is possible by investi-
gating optical state-coordinates, to determine the entirety of those
physical conditions which correspond to “green of this specific sort”
and to subsume them under laws. The same is the case here. It simply
depends on the physical nature of an act — say, of an arm-movement
— whether I can intuitively understand it — as, say, a beckoning-
motion — or not. Consequently, physicalization is possible here too.
The class of arm-movements to which the protocol-designation “beck-
oning motion” corresponds can be determined, and then described
in terms of physical concepts. But perhaps doubts may be raised
as to whether the classification of arm-movements as intelligible or'
unintelligible, and, further, the classification of intelligible arm-
movements as beckoning motions or others really dej>ends, as our
thesis claims, solely on the physical constitution of the arms, the
rest of the body, and the environment. Such doubts are readily re-
moved if, for instance, one thinks of films. We understand the mean-
ing of the action on the movie screen. And our understanding would
doubtless be the same if, instead of the film presented, another
which resembled it in every physical particular were shown. Thus
one can see that both our understanding of meaning and the par-
ticular forms it takes are, in effect, completely determined by the
physical processes impinging on our sense-organs (in the film-
example, those impinging on our optic and auditory sense-organs).

The problem of physicalization in this area, that is, the problem
of the characterization of understandable behavior as such and of
the various kinds of such behavior by means of concepts of sys-
tematized physics, is not as yet solved. But does not then our basic
thesis rest on air? It states that all psychological sentences can be
translated into physical sentences. One may well ask to what extent

4. Erkenntnis, Vol. 11, op. cit., pp. 444 ff. {The Unity of Science, p. 58 ff.).

Psychology in Physical Language [ ]

such a translation is possible, given the present state of our knowl-
edge. Even today every sentence of psychology can be translated
into a sentence which refers to the physical behavior of living crea-
tures. In such a physical characterization terms do indeed occur
which have not yet been physicalized, i.e. reduced to the concepts of
physical science. Nevertheless, the concepts used are physical con-
cepts, though of a primitive sort — ^just as ‘‘warm” and ‘"green’"
(applied to bodies) were physical concepts before one could express
them in terms of physical state-coordinates (temperature and electro-
magnetic field, respectively).

We should like, again, to make the matter clear by using a
physical example. Let us suppose that 'we have found a substance
whose electrical conducti\ity is noticeably raised when it is irradi-
ated by various types of electro-magnetic radiation. We do not yet,
however, know the mtemal structure of this substance and so can-
not yet explain its behavior. We want to call such a substance a
“detector” for radiation of the sort involved. Let tis suppose, further,
that we have not yet systematically determined to what sorts of
radiation the detector reacts. We now discover that the sorts of
radiation to which it responds share still another characteristic, say,
that they accelerate specific chemical reactions. Now suppose that
we are interested in the photo-chemical effects of various sorts of
radiation, but that the determination of these effects, in the case of
a specific sort of radiation, is difficult and time-consuming, while
the determination of the detector’s reaction to it is easy and quickly
accomplished; then we shall find it useful to adopt the detector as a
test-instrument. With its aid we can determine for any particular
sort of radiation whether or not it is likely to have the derired photo-
chemical effect. This practical application will not be impeded by
our ignorance of the detector’s micro-structure and our inability
to explain its reaction in physical terms. In spite of our ignorance,
we can certainly say that the detector isolates a certain physically
specified class of rays. The objection that this is not a physical class
since we cannot characterize it by a specification of optical state-
coordinates but only by the behavior of the detector will not stand.
For to begin with, we know that if we carried out a careful empirical
investigation of the electro-magnetic spectrum, we could identify the
class of rays to which the detector responds. On the basis of this
identffication we could then physicalize the characterization of the
rays in terms of detector-reactions, by substituting for it a charac-
terization in terms of systematic physical concepts. But even our
present way of characterizing the radiation in terms of the detector-

j- lg4 ] RUDOLF CARNAP

test is a physical characterization, though an indirect one. It is dis-
tinguished from the direct characterization wliich is our goal only
through being more circumstantial. There is no diSerence of kind
between the two characterizations, only one of degree, though the
difference of degree is indeed sufficiently great to give us a motive
for pursuing the empirical investigations which might bring the
direct physical characterization within our grasp.

Whether the detector is organic or inorganic is irrelevant to the
epistemological issue involved. The function of the detector is basi-
cally the same whether we are dealing with a physical detector of
specific sorts of radiation or with a tree-frog as a detector of certain
meteorological states of affairs or (if one may believe the news-
papers) with a sniffing dog as a detector of certain human diseases.
People take a practical interest in meteorological forecasts. Where
barometers are not available they may, consequently, use a tree-
frog for the same purpose. But let us be clear about the fact that
this method does not determine the state of the tree-frogs soul, but
a physically specified weather condition, even if one cannot describe
this condition in terms of the concepts of systematized physics.
People, likewise, have a. practical interest in medical diagnoses.
When the directly determinable symptoms do not suffice, they may,
consequently, enlist a dog’s delicate sense of smell for^the purpose.
It is clear to the doctor that, in doing so, he is not determining the
state of the dog’s soul, but a physically specified condition of his
patient’s body. The doctor may not be able, given the present state
of physiological knowledge, to characterize the diseased condition
in question in terms of the concepts of systematic physics. Nonethe-
less, he know's that his diagnosis — whether it is based on the symp-
toms he liirnself has directly observed or on the reactions of the
diagnostic dog — determines nothing and can determine nothing but
the physical condition of his patient. Even apart from this, the
physiologist acknowledges the need for physicaiization. This would
here consist in describing the bodily condition in question, i.e. defin-
ing the disease involved in purely physiological terms (thus elimi-
nating any mention of the dog’s reaction). A further task would
be to trace these back to chemical terms, and these, in turn, to
physical ones.

The case with intuitive psychology is precisely analogous. The
situation here happens to be complicated for epistemological analysis
(though for psychological practice it is simplified) by the fact that
in the examination of an experimental subject the intuitive psycholo-
gist is both the observer and detector. The doctor here is his own

Psychology in Physical Language [ I

diagnostic dog; which, indeed, is also often the case in medical
diagnoses — in their intuitive phases. The psychologist calls the be-
havior of the experimental subject “understandable” or, in a special
case, for instance, “a nod of affirmation,” when his detector re-
sponds to it, or — in our special case — ^when it results in his proto-
cols registering “A nods ^rmatively.” Science is not a system of
experiences, but of sentences; it does not include the psychologist’s
experience of understanding, but rather, his protocol sentence. The
utterance of the psychologist’s protocol sentence is a reaction whose
epistemological function is analogous to the tree-frog’s climbing and
to the barking of the diagnostic dog. To be sure, the psychologist
far surpasses these animals in the variety of his reactions. As a
result, he is certainly very valuable to the pursuit of science. But
this constitutes only a difference of degree, not a difference of kind.

In the light of these considerations, two demands are to be made of
the psychologist. First, we shall expect him (as we expect the doctor)
to be clear about the fact that, in spite of his complicated diagnostic
reaction, he establishes nothing but the existence of some specific
physical condition of the experimental subject, though a condition
which can be characterized only indirectly — ^by his ovn diagnostic
reaction. Secondly, he must acknowledge (as the physiologist does)
that it is a task of scientific research to find a way of physicalizing
the indirect characterization. Psychology’ must determine w^hat are
the physical conditions to which people’s detector-reactions corre-
spond. When this is carried out for even^' reaction of this sort, i.e.
for every result of intuitive understanding, psychological concept for-
mation can be physicalized. The indirect definitions based on detector-
reactions w'il! be replaced by direct definitions in terms of the concepts
of systematized physics. Psychologya like the other scierxes. must and
will reach the level of development at which it can replace the tree-
frog by the barometer. But even in the tree-frog stage psychology
already uses physical language, though of a primitive sort.

6. Physicalization in Graphology

The purpose of this section is not to justify^ physicalism, but only
to show how psychological concepts can in fact be physicalized. To
this end we shall examine a branch of psychology’ in which physical-
ization has already been undertaken with some success. In doing
so we may perhaps also meet the criticism which is occasionally
voiced, that the achievement of physicalization, assuming it were
possible, would in any case be fruitless and uninteresting. It is held

[ 186 ] RUDOLF CARNAF

that, given sufficient information concerning the social group and the
circumstances of the people involved, one might perhaps be able
to specify arm-movements which are interpreted as beckoning-
motions in such a way that they would be characterizable in terms of
kinematic (i.e. spatio-temporal) concepts. But it is alleged that this
procedure would not provide us with any further insist into any-
thing of interest, least of all into the connections of these with other
events.

Remarkably enough, physicalization can show significant success
in a branch of psychology which until comparatively recent times
was pursued in a purely intuitive (or at most a pseudo-rational)
manner and with wholly inadequate empirical data, so that it then
had no claim to scientific status. This is graphology. Theoretical
graphology — we shall concern ourselves here with no other sort —
investigates the law-like relationships which hold between the formal
properties of a person’s handwriting and those of his psychological
properties that are commonly called his ‘‘character.”

We must first of all explain what is meant by character in physical
psychology. Every psychological property is marked out as a dis-
position to behave in a certain way. By “actual property” we shall
understand a property which is defined by characteristics that can be
directly observed: by “disposition” (or “dispositional ;:oncept”> we
shall understand a property which is defined by means of an implica-
tion (a conditional relationship, an if-then sentence). Examples of
familiar dispositional concepts of physics may serve to illustrate this
distinction, and will, at the same time, illustrate the distinction between
occurrent and continuant properties, a distinction which is important
in psychology. An example of a physical occurrent property is a
specific degree of temperature. We define “Body K has temperature
T” to mean “When a sufficiently small quantity of mercury is brought
into contact with K, then ...” When defined in this way, the concept
of temperature is a dispositional concept. Now that physics has
disclosed the micro-structure of matter and determined the laws of
molecular motion, a different definition of temperature is used:
temperature is the mean kinetic energy of molecules. Here, then,
temperature is no longer a dispositional concept, but an actual
property. The occurrent properties of psychology are logically analo-
gous to the familiar dispositional concepts of physics. Indeed, on
our view, they are themselves nothing else than physical concepts.
Example: “Person X is excited” means “If, now, stimuli of such and
such a sort were applied, X would react in such and such a manner”
(both stimuli and reactions being physical events). Here too the

Psychology in Physical Language [ 187 ]

aim of science is to change the form of the definition; more accurate
insight into the micro-structure of the human body should enable
us to replace dispositional concepts by actual properties. That this
is not a utopian aim is shown by the fact that even at the present time,
a more accurate knowledge of physiological macro-events has yielded
us a set of actual characteristics of occurrent states (e.g. for feelings
of various sorts: frequency and intensity of pulse and respiration,
glandular secretion, innervation of visceral muscles, etc.). Such a
change of definitions is markedly more difficult when the states which
have to be delimited are not emotional, for it then presupposes a
knowledge of the micro-structure of the central nervous system which
far surpasses the knowledge currently available.

Physical constants, e.g. heat-conductivity, coefficient of refraction,
etc. might be taken as examples of physical continuant properties.
These too were originally defined as dispositional concepts, e.g. “A
substance has a coefficient of refraction n” means “If a ray of light
enters the substance, then . . . Here again the aim of transforming
the definition has already been achieved for some concepts, and is
being pursued in the case of the remainder. The reference to dispo-
sitions gives way to an actual designation of the composition (in
terms of atoms and electrons ) of the substance in question. The
psychological continuant properties or “character properties” (the
word “character” is here being used in a broad, neutral sense — to
mean more than volitional or attitudinal properties) can, at present,
be defined only in the form of dispositional concepts. Example:
“X is more impressionable than Y” means “If both X and Y have
the same experience under the same circumstances, more intense
feelings are experienced by X than by Y.” In these definitions, both
in the characterization of the stimuli (the statement of the circum-
stances) and in that of the reaction, there are names which still
designate psychological occurrent properties, for which the problem
of physicaiization has not yet been solved. To physicalize the desig-
nations of continuant properties will be possible only when the
designations of occurrent properties have been dealt with. So long
as these are not completely physicalized, the physicaiization of con-
tinuant properties and, as a result, that of characterolog}^ as a whole,
must remain in a scientifically incomplete state, and this no matter
how rich our stock of intuitive knowledge may be.

There is no sharp division between occurrent and continuant
designations. Nonetheless, the difference of degree is large enough
to justify their being differently labelled and differently treated, and,
consequently, large enough to justify the separation of characterology

[ 188 ] RUDOLF CARNAP

from psychology as a whole (considered as the theory of behavior).
Graphology sets itself the task of finding in the features of a person’s
handwriting indications of his character and, to some extent, of his
occurrent properties. The practising graphologist does not intend the
rational method to replace intuition, but only to support or to correct
it. It has, however, become clear that the pursuit of the task of
physicalization will serve even this purpose. Along these lines
graphology has already, of late, made some significant discoveries.

Since the problem of graphology is to discover the correspond-
ences holding between the properties of a person’s handwriting and
those of his character, we may here divide the problem of physical-
ization into three parts. The physicalization of the properties of
handwriting constitutes the first part of the problem. A certain script
gives me, for instance, an intuitive impression of something full and
juicy. In saying so, I do not primarily refer to characteristics of the
writer, but to characteristics of his script. The problem now is to
replace intuitively identified script-properties of this sort by prop-
erties of the script’s shape, i.e. by properties which may be defined
with the aid of geometrical concepts. That this problem can be
solved is clear. We need only thoroughly investigate the system of
forms which letters, words, and lines of script might possibly take
in order to determine which of these forms make the inthitive im-
pression in question on us. So, for instance, we might find that a
script appears full or two-dimensional (as opposed to thin or linear)
if rounded connections are more frequent than angles, the loops
broader than normal, the strokes thicker, etc. This task of the
physicalization of the properties of handwriting has in many cases
been accomplished to a large extent.*'' We are not objecting to the
retention of the intuitively derived descriptions (in terms, for in-
stance, of “full,” “delicate,” “dynamic,” etc.). Our requirement will
be adequately met as soon as a definition in exclusively geometric
terms is provided for each such description. This problem is pre-
cisely analogous to the problem, to which we have frequently re-
ferred, of identifying in quantitative terms those physical conditions
which correspond to a qualitative designation — such as “green of
such and such a sort” — in the protocol language.

The second part of the problem consists of the physicalization
of the character properties referred to in graphological analyses.
The traditional concepts of characterology — ^whose meaning is as a

5. Cj. Klages, L., Handschrift und Character, Leipzig, 1920. Several of our
Examples are taken from this book or suggested by it.

Psychology in Physical Language [ 189 }

rule not clearly defined, but left to be expressed in our everyday
vocabulary or by means of metaphorical language — ^have to be
systematized and given physicalistic (behavioristic) definitions. We
have already seen that such a definition refers to a disposition to
behave in a certain way, and further, that the task of the construc-
tion of such definitions is difficult and presupposes the physicalization
of psychological occurrent properties.

We can see that in both parts of the problem the task is one of
replacing primitive, intuitive concept formations by systematic ones,
of replacing the observer with a tree-frog by the observer with a
barometer (in graphology, as in intuitive medical diagnoses, the ob-
server and the tree-frog coincide).

In addition to these questions there is a third aspect of the
problem to be considered: the basic empirical task of graphology.
This consists of the search for the correlations which hold between
the properties of handwriting and those of character. Here too, a
systematization, though of a different sort, takes place. The cor-
respondence of a specific property of handwriting to a specific prop-
erty of character may, at first, be recognized intuitively — ^for instance,
as a result of an empathetic reflection on the arm-movements which
produced the script in question. The problem of systematization
here is to determine the degree of correlation of the two properties
by a statistical investigation of many instances of script of the type
in question and the characters of the corresponding writers.

Our position now is that the further development and clarifica-
tion of the concepts of psychology as a whole must take the direction
we have illustrated in our examination of graphoIog^^ the direction,
that is, of physicalization. But as we have already emphasized sev-
eral times, psychology is a physical science even prior to such a
clarification of its concepts — a physical science whose assignment it
is to describe systematically the (physical) behavior of living crea-
tures, especially that of human beings, and to develop laws under
which this behavior may be subsumed. These laws are of quite di-
verse sorts. A hand movement, for instance, may be examined from
various aspects: first, semioticaliy, as a more or less conventional
sign for some designated state of affairs; secondly, mimically, as an
expression of the contemporaneous psychological state — the occur-
rent properties of the person in question; thirdly, physiognomically,
as an expression of the continuant properties — ^the character of the
person in question. In order to investigate, say, the hand movements
of people (of certain groups) in their mimical and physiognomic

[ 190 ] RUIX>LF CARNAP

aspects one might perhaps take motion pictures of them, and, from
these, derive kmematic diagrams of the sort which engineers coH”
struct for machine parts. In this manner the shared kmematic (i.e.,
spatio-temporal) characteristics of the hand movements with whose
perception certain intuitive protocol designations tend to be asso-
ciated (e.g. “This hand movement looks rushed,” . . grandiose,”
etc.) would have to be determined. It will now be clear why pre-
cisely graphology — the characterological investigation of writing
movements, a very special sort of hand movements, identifiable in
terms of their specific purpose — should be the only study of this
sort which can as yet show any results. The reason is that writing
movements themselves produce something resembling kinematic
diagrams, namely, the letters on the paper. To be sure, only the
track of the movements is drawn. The passage of time is not recorded
— the graphologist can subsequently only infer this, imperfectly,
from indirect signs. More accurate results would be demonstrable
if the complete three-dimensional spatio-temporal diagram, not only
its projection on the writing plane, were available. But even the
conclusions to which graphology currently subscribes allay what-
ever misgivings there might have been that investigations directed
at the physicalization of psychological concepts would prove to be
uninteresting. It may not even be too rash a conjecture ^hat inter-
esting parallels may be found to hold between the conclusions of
characterological investigations of both the involuntary and the
voluntaiy^ motions of the various parts of the human body on the one
hand, and on the other hand the conclusions of graphology which
are already available to us. If specific properties of a person’s char-
acter express themselves both in a specific form of handwriting and
in a specific form of arm motion, a specific form of leg motion,
specific facial features, etc., might not these various forms resemble
one another? Perhaps, after having first given fruitful suggestions
for the investigation of other sorts of bodily movements, graphology
may, in turn, be stimulated by the results to examine script prop-
erties it had previously overlooked. These, of course, are mere con-
jectures; whether or not they are justifiable cannot affect the ten-
ability of our thesis, which maintains the possibility of translating
all psychological sentences into physical language. This translata-
bility holds regardless of whether or not the concepts of psychology
are physicalized. Physicalization is simply a higher-level, more rigor-
ously systematized scientific form of concept formation. Its accom-
plishment is a practical problem which concerns the psychologist
rather than the epistemologist.

Psychology in Physical Language

[191]

7. Sentences about One’s Own Mind;

“Introspective Psychology”

Our argument has shown that a sentence about other minds
refers to physical processes in the body of the person in question.
On any other interpretation the sentence becomes untestable in
principle, and thus meaningless. The situation is the same with sen-
tences about one’s own mind, though here the emotional obstacles
to a physical interpretation are considerably greater. The relation-
ship of a sentence about one’s own mind to one about someone
else’s may most readily be seen with respect to a sentence about
some past state of one’s own mind, e.g. Pi: “I was excited yester-
day.” The testing of this sentence involves either a rational inference
from protocol sentences of the form of pi — which refer to presently
perceived script, photographs, hlms, etc. originating with me yester-
day; or it involves an intuitive method, e.g. utilizing the protocol
sentence p2, “I recall having been excited yesterday.” The content
of Pi exceeds both that of the protocol sentence pi and that of the
protocol sentence po, as is most clearly indicated by the possibility
of error and disavowal where Pi is concerned. Pi can only be pro-
gressively better confirmed by sets of protocol sentences of the form
of pi and p2. The veiy same protocol sentences, however, also con-
firm the physical sentence P^: “My body was yesterday in that
physical condition which one tends to call ‘excitement.’ ” Pi has,
consequently, the same content as the physical sentence P2.

In the case of a sentence about the present state of one’s own
mind, e.g. Pi: “I now am excited” one must clearly distinguish
between the system sentence Pi and the protocol sentence p2, which,
likewise, may read “I now am excited.” The difference rests in the
fact that the system sentence Pi may, under certain circumstances,
be disavowed, w^hereas a protocol sentence, being an epistemological
point of departure, cannot be rejected. The protocol sentences pi
which rationally support Pi have here some such form as “I feel
my hands trembling,” “I see my hands trembling,” “I hear my
voice quavering,” etc. Here too, the content of Pi exceeds that of
both Pi and p2, in that it subsumes aU the possible sentences of
this sort. Pi has the same content as the physical sentence P2, “My
body is now in that condition which, both under my own observa-
tion and that of others, exhibits such and such characteristics of
excitement,” the characteristics in question being those which are
mentioned both in my own protocol sentences of the sort of pi

[ 192 ] RUTOLF CJffiNAP

and p2 other people’s protocol sentences of corresponding

sorts (discussed above in our example of sentences about other
minds).

The table opposite shows the analogous application of the
physicalist thesis to the three cases we have discussed by exhibiting
the parallelism of sentences about other minds, sentences about
some past condition of one’s own mind, and sentences about the
present condition of one’s own mind, with the physical sentence
about the wooden support.

Objection from introspective psychology: "‘When the psycholo-
gist is not investigating other experimental subjects, but pursues self-
observation, or “introspection,” instead, he grasps, in a direct man-
ner, something non-physical — and this is the proper subject-matter
of psychology.”

Rebuttal. We must distinguish between a question of the justifi-
cation of the use of some prevalent practical method of inquir}* and
a question of the justification of some prevalent interpretation of
the results of that method. Every method of inquir}' is justified; dis-
putes can arise only over the question of the purpose and fruitfulness
of a given method, which is a question our problem does not in-
volve. W^e may apply any method we choose; we cannot however,
interpret the obtained sentences as we choose. Tne meaning of a
sentence, no matter how obtained, can unequivocally be deter-
mined by a logical analysis of the way in which it is derived and
tested. A psychologist who adopts the method of what is called
“introspection” does not thereby expose himself to criticism. Such
a psychologist admits sentences of the form “I have experienced
such and such events of consciousness” into his experiment-protocol
and then arrives at general conclusions of his own by means of
inductive generalization, the construction of hypotheses, and, finally,
a comparison of his hypotheses with the conclusions of other persons.
But again we must conclude, both on logical and epistemological
grounds, that the singular as well as the general sentences must be
interpreted physically. Let us say that psychologist A writes sen-
tence P2: ""(I am) now excited” into his protocol. An earlier investi-
gation^ has shown that the view which holds that protocol sentences
cannot be physically interpreted, that, on the contraiy^ they refer
to something non-physical (something “psychical,” some “experience-
content,” some “datum of consciousness,” etc.) leads directly to
the consequence that every protocol sentence is meaningful only
to its author. If A’s protocol sentence p2 were not subject to a

6. Erkenntnis, Vol. 11, p. 454, (The Unity of Science, pp. 78-79).

THE PHYSICALISTIC INTERPRETATION OF PSYCHOLOGICAL SENTENCES

[ 194 ] RUDOLF CARNAP

physical interpretation, it could not be tested by B, and would, thus,
be meaningless to B. On the previous occasion in question we
showed, further, that the non-physical interpretation leads one into
insoluble contradictions. Finally, we found that every protocol sen-
tence has the same content as some physical sentence,'^ and that
this physical translation does not presuppose an accurate knowledge
of the physiology of the central nervous system, but is feasible even
at present. Sentences about one’s own min d — ^whether one takes
these to be inter-subjective system sentences or so-called introspective
protocol sentences — are thus in every case translatable into sen-
tences of the physical language.

One may perhaps object that there is, after all, a difference be-
tween an experience and an utterance about it, and that not evtry
experience has to be expressed in a protocol sentence. The differ-
ence referred to certainly exists, though we would formulate it
differently. Sentences Pi: ‘'A now sees red” and P^: “A now says
T see red’ ” do not have exactly the same content. Nor does Pi
justify the inference of P2; only the conditional sentence “If this
and that occurs, then Po” may be inferred. For Pi ascribes a physical
state to A of such a kind that, under certain circumstances, it leads
to the event of speaking the sentence referred to ia Po.

If we consider the method in accordance with whicli the con-
clusions of so-called introspection are generally integrated with the
body of scientific knowledge, we shall note that these conclusions
are, indeed, physically evaluated. It so happens that the physicalism
adopted in practice is generally not acknowledged in theory. Psychol-
ogist A announces his experimental results; reader B reads in them,
among others, the sentence “A was excited” (for the sake of clarity
we write “A” instead of the word “I” which B in reading must
replace by “A”). For B, this is a sentence about someone else’s
mind; nothing of its claim can be verified except that A’s body
was in such and such a physical condition at the time referred to.
(We argued this point in our analysis of sentence Pi about someone
else’s mind.) B himself could not, indeed, have observed this con-
dition, but he can now indirectly infer its having existed. For, to
begin with, he sees the sentence in question in a book on whose
title-page A is identified as the author. Now, on the basis of a
general sentence for which he has already obtained indirect evidence,
B infers (with some degree of probability) that A wrote the sen-
tences printed in this book; from this, in its turn, on the basis of

7. Ibid., pp. 457 ff., (The Unity of Science, pp. 84 ff.).

Psychology in Physical Language [ 195 ]

a general sentence, with regard to A’s reliability, for which he again
has good indnctive evidence, B infers that, had he observed A’s
body at the relevant time he would (probably) have been able to
conj&nn the existence of the state of (physical) excitement. Since
this confirmation can refer only to some physical state of A’s body,
the sentence in question can have only a physical meaning for B.

Generally speaJdng, a psychologist’s spoken, written, or printed
protocol sentences, when they are based on so-called introspection,
are to be interpreted by the reader, and so figure in inter-subjective
science, not chiefly as scientific sentences, but as scientific facts. The
epistemological confusion of contemporary psychology stems, to a
large extent, from this confusion of facts in the form of sentences
with the sentences themselves considered as parts of science. (Our
example of the patterns in. the sky is relevant here.) The intro-
spective statements of a psychologist are not, in principle, to be
interpreted any differently from the statements of his experimental
subjects, which he happens to be reporting. The only distinction the
psychologist enjoys is that, when the circumstances justify it, one
may accept his statements as those of an exceptionally reliable and
well-trained experimental subject. Further, the statements of an
experimental subject are not, in principle, to be interpreted differ-
ently from his other voluntary or involuntary movements — though
his speech movements may, under favorable circumstances, be re-
garded as especially informative. Again, the movements of the
speech organs and of the other parts of the body of an experimental
subject are not, in principle, to be interpreted differently from the
movements of any other animal — ^though the former may, under
favorable circumstances, be more valuable in the construction of
general sentences. The movements of an animal are not, again, in
principle, to be interpreted any differently from those of a volt-
meter — ^though under favorable circumstances, animal movements
may serve scientific purposes in more ways than do the movements
of a volt-meter. Finally, the movements of a volt-meter are not, in
principle, to be interpreted differently from the movements of a
raindrop — though the former offer more opportunities for draw-
ing inferences to other occurrences than do the latter. In all these
cases, the issue is basically the same: from a specific physical sen-
tence, other sentences are inferred by a causal argument, i.e. with
the help of general physical formulae — ^the so-called natural laws.
The examples cited differ only in the degree of fruitfulness of their
premises. Volt-meter readings will, perhaps, justify the inference
of a greater number of scientifically important sentences than the

[ 196 ] RUDOLF CARNAP

behavior of some speciic raindrop will; speech movements wUl, in
a certain respect, justify more such inferences than other human
bodily movements wiU. Now, in the case with which we are con-
cerned here, the inference from the sign to the state of affairs signi-
fied has a quite remarkable form. In using someone’s introspective
statement about the state of his own mind (e.g. A’s statement; “A is
excited”), the statement, taken as an acoustic event, is the sign;
under favorable conditions, which are frequently satisfied in scien-
tific contexts, the state of affairs referred to is such that it can be
described by a sentence (“A is excited”) of the very same form
as the acoustic event which functions as a sign of it. [The requisite
conditions are that the person in question be considered reliable and
qualified to make psychological reports, and further that the lan-
guage of these reports be the same as that of the scientific system.]
This identity of the form of the acoustic fact and the scientific sen-
tence which is to be inferred from it explains why the two are so
easily and so obstinately confused. The disastrous muddle into which
this confusion leads us is cleared up as soon as we realize that here,
as in the other cases cited, it is only a question of drawing an in-
ference from a sign to that which it indicates.

It becomes all the more clear that so-called introspective state-
ments caxmot be given a non-physical interpretation when we con-
sider how' their use is learned. A tired child says “Now I am happy
to be in bed.” If we investigated how the child learned to talk
about the states of his own mind we would discover that, under
similar circumstances, his mother had said to him, “Now you are
happy to be in bed.” Thus we see that A learns to use the protocol
sentence p2 from B — who, however, interprets this series of words
as constituting the system sentence P2, a sentence, for B, about
someone else’s mind. Learning to talk consists of B’s inducing a
certain habit in A, a habit of “verbalizing” (as the behaviorists
put it) in a specific manner in specific circumstances. And, indeed
one tends so to direct this habit that the series of words produced
by the speech movements of the child A coincides with the sentence
of the intersubjective physical language which not only describes the
appropriate state of A, but — and this is the essential point — describes
A’s state as B perceives it, that is, the physical state of A’s body.
The example of the child shows this especially clearly. The sen-
tence, “You are happy,” spoken by the mother, is a sentence about
someone else’s mind, and thus, according to our earlier analysis,
can designate nothing but some physical state of affairs. The child
is thus induced to develop the habit of responding to specific cir-

Psychology in Physical Language [ 197 ]

cumstaEces by utteriiig a sentence which expresses a physical state
observed by some other person (or inferred by some other person
from observed signs). If the child utters the same sounds again on
some other occasion, no more can be inferred than that the child’s
body is again in that physical state.

8. Summary

So-called psychological sentences — whether they are concrete
sentences abomt other minds, or about some past condition of one’s
own mind, or about the present condition of one’s own mind, or,
finally, general sentences — are always translatable into physical
language. Specifically, every psychological sentence refers to physical
occurrences in the body of the person (or persons) in question. On
these grounds, psychology is a part of the domain of unified science
based on physics. By “physics” we wish to mean, not the system
of currently known physical laws, but rather the science character-
ized by a mode of concept formation which traces ever}^ concept
back to state-coordinates, that is, to systematic assignments of num-
bers to space-time points. Understanding “physics” in this way, we
can rephrase our thesis — a particular thesis of physicalism — as fol-
lows: psychology is a branch of physics.

REMARKS BY THE AUTHOR (1957)

I would still maintain the essential content of the main thesis
of this article, I would today modify some special points. Perhaps the
most important of them is the following. In the article I regarded a
psychological term, say “excited,” as designating a state characterized
by the disposition to react to certain stimuli with overt behavior of
certain kinds. This may be admissible for the psychological concepts
of eveiy^day language. But at least for those of scientific psychology, as
also of other fields of science, it seems to me more in line with the
actual procedure of scientists, to introduce them not as disposition
concepts, but rather as theoretical concepts (sometimes called “hypo-
thetical constructs”). This means that they are introduced as primitives
by the postulates of a theory, and are connected with the terms of the
observ^ation language, which designate observable properties, by so-
called rules of correspondence. This method is explained and discussed
in detail in my article “The Methodological Character of Theoretical
Concepts,” in H. Feigl and M. Scriven, (eds., Minnesota Studies in the
Philosophy of Science ^ Vol. 1.

{ 198 ] RUDOLF CARNAP

The main thesis of physicalism remains the same as before. It says
that psychological statements, both those of everyday life and of
scientific psychology, say something about the physical state of the
person in question. It is different from the corresponding statements in
terms of micro-physiology or micro-physics (which at the present stage
of scientific development are not yet known, comp. § 4A above) by
using the conceptual framework of psychology instead of those of
the two other fields. To find the specific features of the correspondence
will be an empirical task (comp. § 6, the third part of the procedure of
physicaiization). Once known, the correspondence can be expressed by
empirical laws or, according to our present view, by theoretical pos-
tulates. Our present conception of physicalism, the arguments for it,
and the development which led to it, are represented in the following
two articles by Herbert Feigi: (1) “Physicalism, Unity of Science and
the Foundations of Psychology,” in: P. A. Schilpp, editor, The Philos-
ophy of Rudolf Carnap (Library of Living Philosophers); see also my
reply to Feigi in the same volume; (2) “The ‘Mental’ and the ‘Physical,’’’
in Voi. n of Minnesota Studies in Philosophy of Science.

9

Protocol Sentences

BY OTTO NEURATH

(translated by GEORGE SCHICK)

With the progress of knowledge, the number of expressions which
are formulated with a high degree of precision in the language of
Unified Science is continually on the increase. Even so, no such
scientific term is wholly precise; for they are ail based upon terms
which are essential for protocol sentences; and it is immediately
obvious to eveiy'one that these terms must be vague.

The fiction of an ideal language constructed out of pure atomic
sentences is no less metaphysical than the fiction of Laplace’s demon.
The language of science, with its ever increasing development of
symbolic systems, cannot be regarded as an approximation to such
an ideal language. The sentence “Otto is observing an angry^ person”
is less precise than the sentence “Otto is observing a thermometer
reading 24 degrees,” insofar as the expression “angry person” can-
not be so exactly defined as “thermometer reading 24 degrees.” But
“Otto” itself is in many w^ays a vague term. The phrase “Otto is
observing” could be replaced by the phrase “The man, whose care-
fully taken photograph is listed no. 16 in the file, is observing”:
but the term “photograph listed no. 16 in the file” still has to be
replaced by a system of mathematical formulae, which is unam-
biguously correlated with another system of mathematical formulae,

This article first appeared in Volume III of Erkenntnis (1932/33). It is published
here with the kind permission of Mrs. Marie Neurath and Professor Rudolf Carnap.
At the beginning of Ms article Neurath had the following note: “References will be
to Rudolf Carnap’s article, ‘Die Physikaiische Sprache als Universaisprache der
Wissenschaft,’ Erkenntnis, 1932, VoL II, pp. 432ff.* Since there is widespread
agreement with Carnap, we shall adopt his terminology. So that I need not repeat
what I have already w-ritien elsewhere, I refer the reader to my articles ‘Physikal-
ismus,’ Scientia, 1931, pp. 297 ff. and ‘Soziologie im Physikaiismus,’ Erkenntnis,
VoL n, 1932, pp. 393 ff.’’

[* There is an English translation of this article by Max Black under the title
“The Unity of Science.” It was published as a monograph by Kegan Paul, London.]

'f! f ;

f w.

[ 200 ] OTTO NEUEATH

the terms of which take the place of ‘‘Otto,” “angry Otto,” “friendly
Otto,” etc.

"^at is originally given to us is our ordinary natural language
with a stock of imprecise, unanalyzed terms. We start by purifying
this language of metaphysical elements and so reach the physicalistic
ordinary language. In accomplishing this we may fund it veiy^ useful
to draw up a list of proscribed words.

There is also the physicalistic language of advanced science
which we can so construct that it is free from metaphysical elements
from the start. We can use this language only for special sciences,
indeed only for parts of them.

If one wished to express aU of the unified science of our time in
one language, one would have to combine terms of ordinary language
with terms of the language of advanced science, since, in practice,
the two overlap. There are some terms which are used only in
ordinary language, others which occur only in the language of ad-
vanced science, and still others which appear in both languages.
Consequently, in a scientific treatise concerned with the entire field
of unified science only a “slang” comprising words of both languages
will serve.

We believe that every word of the physicalistic ordinary' language
will prove to be replaceable by terms taken from the language of
advanced science, just as one may also formulate the terms of the
language of advanced science with the help of the terms of ordi-
nary language. Only the latter is a very unfamiliar proceeding, and
sometimes not easy. Einstein’s theories are expressible (somehow)
in the language of the Bantus — but not those of Heidegger, unless
linguistic abuses to which the German language lends itself are intro-
duced into Bantu. .4 physicist must, in principle, be able to satisfy
the demand of the talented writer who insisted that: “One ough\
to be able to make the outlines of any rigorously scientific thesis
comprehensible in his own terms to a hackney-coach-driver.”

The language of advanced science and ordinary language coin-
cide today primarily in the domain of arithmetic. But, in the system
of radical physicalism, even the expression “2 times 2 is 4,” a
tautology, is linked to protocol sentences. Tautologies are defined in
terms of sentences which state how tautologies function as codicils
appended to certain commands under certain circumstances. For
instance: “Otto says to Karl ‘Go outside when the flag waves and
when 2 times 2 is four.’ ” The addition of the tautology here does
not alter the effect of the command.

Even considerations of rigorous scientific method restrict us to

Frotocol Sentences [ 201 ]

the use of a “universal slang" Since there is as yet no general agree-
ment as to its composition, each scholar who concerns himself with
these matters must utilize a universal slang to which he himself has
contributed new terms.

There is no way of taking conclusively established pure protocol
sentences as the starting point of the sciences. No tabula rasa
exists. We are like sailors who must rebuild their ship on the open
sea, never able to dismantle it in dry-dock and to reconstruct it
there out of the best materials. Only the metaphysical elements can be
allowed to vanish without trace. Vague linguistic conglomerations
always remain in one way or another as components of the ship.
If vagueness is diminished at one point, it may well be increased
at another.

We shall from the ver\^ first, teach children the universal-slang
— ^purged of all metaphysics — as the language of the historically
transmitted unified science. Each child vdll be so trained that it
starts with a simplified universal-slang, and advances gradually to
the use of the universal-slang of adults. In this connection, it is
meaningless to segregate this children's language from that of the
adults. One would, in that case, have to distinguish several universal-
slangs. Tne child does not learn a prlmiiive universal-slang from,
which the universal-slang of the adults derives. He learns a ‘"poorer”
universal-slang, which is gradnaily filled in. The expression “ball
of iron” is used in the language of adults as well as in that of chil-
dren. In the former it is defined by a sentence in which terms such
as “radius” and ‘V” occur, while in the children’s definition words
such as “nine-pins,” “present from Uncle Rudi,” etc. are used.
But “Uncle Rudi” also crops up in the language of rigorous science,
if the physical ball is defined by means of protocol sentences in
which “Uncle Rudi” appears as “the observer who perceives a ball.”

Carnap, on the other hand, speaks of a primitive protocol lan-
guage.^ His comments on the primitive protocol language — on the
protocol sentences which “require no verification” — are only mar-
ginal to his significant anti-metaphysical views, the mainspring of
which is not affected by the objections here brought forward, Carnap
speaks of a primaiy^ language, also referred to as an experiential or
as a phenomenalistic language. He maintains that “at the present
stage of inquiry, the question of the precise characterization of this
language cannot be answered.” These comments might induce

1. Op, cit., Erkenntnis, VoL II, pp, 437 2. and 453 S. (Unity of Science, pp.
42 2. and 76 2.).

[ 202 ] OTTO NEORATH

younger men to search for a protocol language of the sort described;
and this might easily lead to metaphysical deviations. Although
metaphysical speculation cannot altogether be restrained by argu-
ment, it is important, as a means of keeping waverers in line, to
maintain physicalism in its most radical version.

Apart from tautologies, unified science consists of factual sen-
tences. These may be sub-divided into

(a) protocol sentences

(b) non-protocol sentences.

Protocol sentences are factual sentences of the same form as the
others, except that, in them, a personal noun always occurs several
times in a specific association with other terms. A complete protocol
sentence might, for instance, read: “‘Otto’s protocol at 3:17 o’clock:
[At 3:16 o’clock Otto said to himseK: (at 3:15 o’clock there was
a table in the room perceived by Otto)].” This factual sentence is
so constructed that, within each set of brackets, further factual sen-
tences may be found, viz-: “At 3:16 o’clock Otto said to himself: (At
3:15 o’clock there was a table in the room perceived by Otto)” and
“At 3:15 o’clock there was a table in the room perceived Ijy Otto.”
These sentences are, however, not protocol sentences.

Each term occurring in these sentences may, to some extent, be
replaced at the veiy^ outset by a group of terms of the language of
advanced science. One may introduce a system of physicalistic desig-
nations in place of “Otto,” and this system of designations may, in
turn, further be defined by referring to the “position” of the name
“Otto” in a group of signs composed of the names “Karl,” “Hein-
rich,” etc. All the words used in the expression of the above protocol
sentence are either words of the universal-slang or may without diffi-
culty be replaced at any moment by words of the universal-slang.

For a protocol sentence to be complete it is essential that the
name of some person occur in it.“Now joy,” or “Now red circle,”
or “A red die is lying on the table” are not complete protocol sen-
tences.^ They are not even candidates for a position within the inner-
most set of brackets. For this they would, on our analysis, at least
have to read “Otto now joy,” or “Otto now sees a red circle,” or
“Otto now sees a red die lying on the table” — ^which would roughly
correspond to the children’s language. That is, in a full protocol sen-

2. Cf. Carnap, op. cit., Erkenntnis, VoL II, pp. 438 ff. {Unity of Science, pp.

Frotocol Sentences [ ]

tence the expression within the innennost set of brackets is a sentence
which again features a personal nonn and a term from the domain
of perception-terms. The relative extent to which terms of ordinary
langnage and of the language of advanced science are used is of
no significance, since the universal-slang may be used with consid-
erable flexibility.

The expression “said to himself,” after the first bracket, recom-
mends itself when, as above, one wants to construct various groups
of sentences, as, for instance, sentences incorporating reality-terms,
or hailucination-terms, or dream-terms, and especially when one
wants to identify unreality as such. For instance, one could say:
“Otto actually said to himself, There was nothing in the room but
a bird perceived by Otto’ but, in order to amuse himself, he wrote,
‘There w^as nothing in the room but a table perceived by Otto.’ ” This
is especially pertinent to the discussion in the next section, in
which we reject Carnap’s thesis to the efieci that protocol sentences
are those “which require no verification.”

The transformation of the sciences is effected by the discarding
of sentences utilized in a previous historical period, and, frequently,
their replacement by others. Sometimes the same form of words is
retained, but their defiunitions are changed. Every Icnv and every
physicalistic sentence of unified-science or of one of its sub-sciences
is subject to such change. And the same holds for protocol sentences.

In unified science we tiy’ to construct a non-contradictory system
of protocol sentences and non-protocol sentences (including laws).-
When a new sentence is presented to us we compare it with the
system at our disposal, and determine whether or not it conflicts
with that system. If the sentence does conSict wdth the system, we
may discard it as useless (or false), as, for instance, w’ould be done
with “In Africa lions sing only in major scales.” One may, on the
other hand, accept the sentence and so change the system that it
remains consistent even after the adjunction of the new' sentence.
The sentence would then be called “true.”

The fate of being discarded may befall even a protocol sentence.
No sentence enjoys the noli me tangere w^hich Carnap ordains for
protocol sentences. Let us consider a particularly drastic example.
We assume that we are acquainted with a scholar called “Kaion,”
who can write with both hands simultaneously. He writes with his
left hand, “Kalon’s protocol at 3:17 o’clock: [At 16 minutes 30

3. Cf. Carnap, op. cit., Brkenntnis, VoL II, pp. 439 ff. {Unity of Science, pp.
47 ff.).

[ 204 ] OTTO NEimATH

seconds past 3 o’clock Kalon said to himself: (There was nothing
in the room at 3:16 o’clock except a table perceived by Kalon)].”
At the same time, with his right hand, he writes, ‘‘Kalon’s protocol
at 3:17 o’clock: [At 16 minutes 30 seconds past 3 o’clock Kalon
said to himself: (There was nothing in the room at 3:16 o’clock
except a bird perceived by Kalon)].” What is he — and what are
we — to make of the conjunction of these two sentences? We may,
of course, make statements such as ‘‘Marks may be found on this
sheet of paper, sometimes shaped this way and sometimes that.”
With respect to these marks on paper, however, Carnap’s word
“verification” finds no application. “Verification” can only be used
with reference to sentences, that is, with reference to sequences of
marks which are used in a context of a reaction-test and which may
systematically be replaced by other marks.- Synonymous sentences
may be characterized as stimuli which under specific reaction-tests
evoke the same responses. Chains of ink-marks on paper and chains
of air-vibrations which may under specific conditions be co-ordinated
with one another are called “sentences.”

Two conflicting protocol sentences cannot both be used in the
system of unified science. Though we may not be able to tell which
of the two is to be excluded, or whether both are not to be excluded,
it is clear that not both are verifiable, that is, that both^do not fit
into the system.

If a protocol sentence must in such cases be discarded, may not
the same occasionally be called for when the contradiction between
protocol sentences on the one hand and a system comprising proto-
col sentences and non-protocol sentences (laws, etc.) on the other
is such that an extended argument is required to disclose it? On
Carnap’s view, one could be obliged to alter only non-protocol
sentences and laws. We also allow for the possibility of discarding
protocol sentences. A defining condition of a sentence is that it be
subject to verification, that is to say, that it may be discarded.

Carnap’s contention that protocol sentences do not require veri-
fication, however it may be understood, may without difficulty be
related to the belief in immediate experiences which is current in
traditional academic philosophy. According to this philosophy there
are, indeed, certain basic elements out of which the world-picture is
to be constructed. On this academic view, these atomic experiences
are, of course, above any kind of critical scrutiny; they do not re-
quire verification.

Carnap is trying to introduce a kind of atomic protocol, with

4. Cf. my article in Scientia, p. 302.

Protocol Sentences [ 205 ]

Ms demand that “a clear-cut distinction be made in scientific pro-
cedure between the adoption of a protocol and the interpretation of
the protocol sentences,” as a result of which “no indirectly acquired
sentences would be accepted into the protocol.”^ The above for-
mulation of a complete protocol sentence shows that, insofar as
personal nouns occur in a protocol, interpretation must always
already have taken place. When preparing scientific protocols, it
may be useful to phrase the expression within the innermost set of
brackets as simply as possible, as, for instance, “At 3 o'clock Otto
was seeing red,” or — another protocol — “At 3 o’clock Otto was
hearing C sharp,” etc. But a protocol of such a sort is not primitive
in Carnap’s sense, since one cannot, after all, get around Otto’s
act of perception. There are no sentences in the universal-slang
which one may characterize as “more primitive” than any others.
All are of equal primitiveness. Personal nouns, words denoting per-
ceptions, and other words of little prhniiiveness occur in ail factual
sentences, or, at least, in the hypotheses from which they derive.
All of which means that there are neither primitive protocol sentences
nor sentences which are not subject to verification.

The universal-siapg, in the sense explained above, is the same
for the child as for the adult. It is the same for a Robinson Crusoe
as for a human society. If Crusoe wants to relate what he registered
(“protokolliert”) yesterday with what he registers today, that is,
when he wants to have any sort of recourse to a language, he cannot
but have recourse to the inter-subjective language. The Crusoe of
yesterday and the Crusoe of today stand to one another in pre-
cisely the relation in which Crusoe stands to Friday. Consider a
man who has both lost his memoiy* and been blinded, who is now
learning afresh to read and to write. The notes which he himself
took in the past and which now, with the aid of a special apparatus,
he reads again are for him as much the notes of some other man
as notes actually written by someone else. And the same would
still be the case after he had realized the tragic nature of his cir-
cumstances, and had pieced together the story of his life.

In other words, every language as such is inter-subjective. The
protocols of one moment must be subject to incorporation in the
protocols of the next, just as the protocols of A must be subject
to incorporation in the protocols of B. It is therefore meaningless
to talk, as Carnap does, of a private language, or of a set of dis-
parate protocol languages which may ultimately be dra\^m together.

5. Op. ciL, p. 437 {Unity of Science, p. 42).

[ 206 ] OTTO NEURATH

The protocol languages of the Crusoe of yesterday and of the Crusoe
of today are as close and as far apart from one another as are the
protocol languages of Crusoe and of Friday. If, under certain cir-
cumstances, the protocol languages of yesterday’s Crusoe and of
today’s are called the same language, then one may also, under
the same circumstances, call the protocol language of Crusoe and
that of Friday the same language.

In Carnap’s writings we also encounter an emphasis on the ‘T’
familiar to us from idealistic philosophy. In the universal-slang it
is as meaningless to talk of a personal protocol as to talk of a here
or a now. In the physicalistic language personal nouns are simply
replaced by co-ordinates and coefficients of physical states. One can
distinguish an Otto-protocol from a KarUprotocol, but not a proto-
col of one’s own from a protocol of others. The whole puzzle of
other minds is thus resolved.

Methodological solipsism and methodological positivism^ do not
become any the more serviceable because of the addition of the
word ‘‘methodological.”^

For instance, had I said above, “Today, the 27th of July, I ex-
amine protocols both of my own and of others,” it would have been
more correct to have said “Otto Neurath’s protocol at 10:00 a.m.,
July 27, 1932; [At 9:35 o’clock Otto Neurath said to himself: (Otto
Neurath occupied himself between 9:40 and 9:57 with a protocol
by Neurath and one by Kalon, to both of which the following two
sentences belong: . . .)].” Even though Otto Neurath himself for-
mulates the protocol concerning the utilization of these protocols,
he does not link his own protocol with the system of unified science
in any different way from that in which he links Kalon’s. It may well
happen that Neurath discards one of Neurath’s protocols, and adopts
in its stead one of Kalon’s. The fact that men generally retain their
own protocol sentences more obstinately than they do those of
other people is a historical accident which is of no real significance
for our purposes. Carnap’s contention that “every individual can
adopt only his own protocol as an epistemological basis” cannot be
accepted, for the argument presented in its favor is not sound: “Si
can, indeed, also utilize the protocol of So — and the incorporation
of both protocol languages in physicalistic language makes this utili-
zation particularly easy. The utilization is, however, indirect: Si
must first state in his own protocol that he sees a piece of writing

6. Cf. Carnap, op. cit., Erkenntnis, Vol. II, p. 461 (Unity of Science, p. 93).

7. Cf. my article in. Erkenntnis, VoL 11, p. 401. [Translated in the present volume,
see p. 282 below.]

Protocol Sentences [ ]

of such and such a form.”^ But Neurath must describe Neurath's
protocol in a manner analogous to that in which he describes Kalon's!
He describes how Neurath’s protocol looks to him as well as how
Kalon’s does.

In this way we can go on to deal with everyone’s protocol sen-
tences. Basically, it makes no difference at all whether Kalon works
with Kalon’s or with Neurath’s protocols, or whether Neurath oc-
cupies himself with Neurath’s or with Kalon’s protocols. In order
to make this quite clear, we could conceive of a sorting-machine
into which protocol sentences are thrown. The laws and other factual
sentences (including protocol sentences) serving to mesh the ma-
chine’s gears sort the protocol sentences which are thrown into the
machine and cause a beU to ring if a contradiction ensues. At this
point one must either replace the protocol sentence whose intro-
duction into the machine has led to the contradiction by some other
protocol sentence, or rebuild the entire machine. Who rebuilds the
machine, or whose protocol sentences are thrown into the machine
is of no consequence whatsoever. Anyone may test his own protocol
sentences as well as those of others.

Summing Up:

Unified science utilizes a universal-slang, in which terms of the
physicalistic ordinary language necessarily also occur.

Children can be trained to use the universal-slang. Apart from
it we do not employ any specially distinguishable “basic” protocol
sentences, nor do different people make use of different protocol
languages.

We find no use in unified science for the expressions “methodo-
logical solipsism” and “methodological positivism.”

One cannot start with conclusively established, pure protocol
sentences. Protocol sentences are factual sentences like the others,
containing names of persons or names of groups of people linked
in specific ways with other terms, which are themselves also taken
from the universal-slang.

The Vienna Circle devotes itself more and more to the task of
expressing unified science (which includes sociology as well as
chemistry, biology as well as mechanics, psychology — ^more properly
termed “behavioristics” — as well as optics) in a unified language,
and with the displaying of the inter-connections of the various
sciences which are so often neglected; so that one may without

8. Cf. Camap, op. ciu, Erkenntms, Vol. 11, p. 461 (The Unity of Science, p. 93).

[ 208 ] OTTO NEimATH

difficulty relate the terms of any science to those of any other. The
word “man” which is prefixed to “makes assertions” is to be defined
in just the same way as the word “man” occurring in sentences which
contain the words “economic system” and “production.”

The Vienna Circle has received powerful encouragement from
various sources. The achievements of Mach, Poincare, and Duhem
have been turned to as good account as the contributions of Frege,
Schroder, and Russell. Wittgenstein’s writings have been extraordin-
arily stimulating, both through what has been taken from them and
through what has been rejected. His original plan — to use philosophy
as a ladder which it is necessary to climb in order to see things clearly
— ^may, however, be considered to have come to grief. The main
issue in this, as in all other intellectual activities, will always be to
bring the sentences of unified science — both protocol sentences and
non-protocol sentences — into consonance with one another. For
this, a logical syntax of the sort toward which Carnap is working
is required — Carnap’s logical reconstruction of the world being the
first step in this direction.

The discussion I have initiated here — ^for Carnap will certainly
find much in the corrections to correct again and to develop — serves,
as do so many of our other efforts, to secure ever more firmly the
common, broad foundations on which all the adherents (rf physicalism
base their studies. Discussions of peripheral issues, such as this
one, are, however, going to play a continuously diminishing role. The
rapid progress of the work of the Vienna Circle shows that the
planned co-operative project dedicated to the construction of unified
science is in constant development. The less time we find it necessary
to devote to the elimination of ancient confusions and the more we
can occupy ourselves with the formulation of the inter-connections
of the sciences, the quicker and more successful will this construction
be. To this end it is of the first importance that we learn how to use
the physicalistic language, on behalf of which Carnap, in his article,
entered the lists.

10

The Foundation of Knowledge
BY MORITZ SCHLICK
(translated by DAVID RYNIN)

All mportant attempts at establisiimg a theory of knowledge
grow" out of the problem concerning the certainty of human knowl-
edge. And this problem in turn originates in the wish for absolute
certaiiit}\

The insight that the statements of daily life and science can at
best be only probable, that even the most general results of science,
which all experiences confirm, can have only the character of
hypotheses, has again and again stimulated philosophers since
Descartes, and indeed, though less obviously, since ancient times, to
search for an unshakeable, indubitable, foundation, a firm basis
on which the uncertain structure of our knowledge could rest. The
uncertaint}^ of the structure was generally attributed to the fact that
it was impossible, perhaps in principle, to construct a firmer one
by the power of human thought. But this did not inhibit the search
for the bedrock, which exists prior to all construction and does not
itself vacillate.

This search is a praiseworthy, healthy effort, and it is prevalent
even among “relativists” and “sceptics, who would rather not ac-
knowledge it.” It appears in different forms and leads to odd dif-
ferences of opinion. The problem of “protocol statements,” their
structure and function, is the latest form in which the philosophy or
rather the decisive empiricism of our day clothes the problem of
the ultimate ground of knowledge.

What was originally meant by “protocol statements,” as the
name indicates, are those statements which express the facts with ab-
solute simplicity, without any moulding, alteration or addition, in
whose elaboration every science consists, and which precede all know-

This article, originally entitled “Dber das Fundament der Erkenntnis,” first ap-
peared in Erkenntnis, VoL IV (1934). It is published here with the kind permission
of Mrs. Schlick and Professor Camap.

£209 ]

MORITZ SCHLICK

[210]

mg, every judgment regarding the world It makes no sense to speak
of uncertain facts. Only assertions, only our knowledge can be
uncertain. If we succeed therefore in expressing the raw facts in
“protocol statements,” without any contamination, these appear
to be the absolutely indubitable starting points of all knowledge.
They are, to be sure, again abandoned the moment one goes over
to statements winch are actually of use in life or science (such a
transition appears to be that from “singular” to “universal” state-
ments), but they constitute nevertheless the firm basis to which all
our cognitions owe whatever validity they may possess.

Moreover, it makes no difference whether or not these so-called
protocol statements have ever actually been made, that is, actuaffy
uttered, written down or even only explicitly “thought”; it is required
only that one know what statements form the basis for the notations
which are actually made, and that these statements be at all times
reconstructible. If for example an investigator makes a note, “Under
such and such conditions the pointer stands at 10.5,” he knows that
this means “two black lines coincide,” and that the words “under
such and such conditions” (which we here imagine to be specified)
are likewise to be resolved into definite protocol statements which,
if he wished, he could in principle formulate exactly, although per-
haps with difficulty. ^

It is clear, and is so far as I know disputed by no one, that
knowledge in life and science in some sense begins with confirmation of
facts, and that the “protocol statements” in which this occurs stand in
the same sense at the beginning of science. What is this sense? Is
“beginning” to be understood in the temporal or logical sense?

Here we already find much confusion and oscillation. If I said
above that it is not important whether the decisive statements have
been actually made or uttered, this means evidently that they need
not stand at the beginning temporally, but can be arrived at later
just as well if need be. The necessity for formulating them would arise
when one wished to make clear to oneself the meaning of the statement
that one had actually written down. Is the reference to protocol state-
ments then to be understood in the logical sense? In that event they
would be distinguished by definite logical properties, by their struc-
ture, their position in the system of science, and one would be
confronted with the task of actually specitying these properties. In
fact, this is the form in which, for example, Carnap used explicitly
to put the question of protocol statements, while later^ declaring it
to be a question which is to be settled by an arbitrary decision.

1. See Carnap, “Ober ProtokoUsatze,” Erkennmis, Vol. Ill, pp. 216 ff.

The Foundation of Knowledge [211 ]

On the other hand, we find many expositions which seem to pre-
suppose that by “protocol statements” only those assertions are to
be understood that also temporally precede the other assertions
of science. And is this not correct? One must bear in mind that it
is a matter of the ultimate basis of knowledge of reality, and that it
is not sufficient for this to treat statements as, so to speak, “ideal
constructions” (as one used to say in Platonic fashion), but rather
that one must concern oneself with real occurrences, with events that
take place in time, in which the making of judgments consists,
hence with psychic acts of “thought,” or physical acts of “speak-
ing” or “writing.” Since psychic acts of judgment seem suitable
for establishing inter-subjectively valid knowledge only when trans-
lated into verbal or written expressions (that is, into a physical
system of symbols) “protocol statements” come to be regarded
as certain spoken, written or printed sentences, i.e., certain symbol-
complexes of sounds or printer’s ink, which when translated from
the common abbreviations into full-fledged speech, would mean
something like: “Mr. N. N. at such and such a time observed so and
so at such and such a place.” (This view was adopted particularly
by O. Neurath).- As a matter of fact, when we retrace the path
by which we actually arrive at all our knowledge, we doubtless
always come up against this same source: printed sentences in books,
words out of the mouth of a teacher, our own observations (in the
latter case we are ourselves N. N. ) .

On this view protocol statements would be real happenings in
the world and would temporally precede the other real processes
in which the “construction of science,” or indeed the production of
an individual’s knowledge consists.

I do not know to what extent the distinction made here between
the logical and temporal priority of protocol statements corresponds
to differences in the views actually held by certain authors — but
that is not important. For we are not concerned to determine who
expressed the correct view, but what the correct view is. And for this
our distinction between the two points of view will serve well enough.

As a matter of fact, these two views are compatible. For the
statements that register simple data of observation and stand tem-
porally at the beginning could at the same time be those that by
virtue of their structure would have to constitute the logical starting-
point of science.

2. Neurath, "‘ProtokoUsatze,” Erkenntnis, Voi. Ill, pp. 104 S. (Tiiis article is
translated in the present volume, see pp. 199-208 above.)

[ 212 ]

MORITZ SCHLICK

II

The question which wiU first interest us is this: What progress
is achieved by formulating the problem of the ultimate basis of
knowledge in terms of protocol statements? The answer to this
question will itseK pave the way to a solution of the problem.

I think it a great improvement in method to try to aim at the
basis of knowledge by looking not for the primary facts but for the
primary sentences. But I also think that this advantage was not made
the most of, perhaps because of a failure to realize that what was
at issue, fundamentally, was just the old problem of the basis. I be-
lieve, in fact, that the position to which the consideration of protocol
statements has led is not tenable. It results in a peculiar relativism,
which appears to be a necessaiy’^ consequence of the \iew that proto-
col statements are empirical facts upon which the edifice of science
is subsequently built.

That is to say: when protocol statements are conceived in this
manner, then directly one raises the question of the certainty with
which one may assert their truth, one must grant that they are ex-
posed to all possible doubts.

There appears in a book a sentence which says, for example,
that N. N. used such and such an instrument to mikt such and such
an observation. One may under certain circumstances have the
greatest confidence in this sentence. Nevertheless, it and the observa-
tion it records, can never be considered absolutely certain. For the
possibilities of error are innumerable. N. N. can inadvenently or in-
tentionally have described something that does not accurately repre-
sent the observed fact; in writing it down or priming it, an error may
have crept in. indeed the assumption that the symbols of a book
retain their form even for an instant and do not “of themselves”
change into new sentences is an empirical hypothesis, which as such
can never be strictly verified. For eveiy verification would rest on
assumptions of the same sort and on the presupposition that our
memory does not deceive us at least dunng a brief interval, and
so on.

This means, of course — and some of our authors have pointed
this out almost with a note of triumph — ^that protocol statements, so
conceived, have in principle exactly the same character as all the other
statements of science: they are hypotheses, nothing but hypotheses.
They are anything but incontrovertible, and one can use them in the
construction of the system of science only so long as they are sup-

The Foundation of Knowledge [213]

ported by, or at least not contradicted by, other hypotheses. We
therefore always reserve the right to make protocol statements sub-
ject to correction, and such corrections, quite often indeed, do occur
when we eliminate certain protocol statements and declare that they
must have been the result of some error.

Even in the case of statements which we ourselves have put for-
ward we do not in principle exclude the possibility of error. We
grant that our mind at the moment the judgment was made may have
been wholly confused, and that an experience which we now say we
had two minutes ago may upon later examination be found to have
been an hailucination, or even one that never took place at all.

Thus it is clear that on this view of protocol statements they do
not provide one who is in search of a firm basis of knowledge with
anything of the sort. On the contrary, the actual result is that one
ends by abandoning the original distinction between protocol and
other statements as meaningless. Thus we come to understand how
people come to think^ that any statements of science can be selected
at will and called “protocol statements,” and that it is simply a
question of convenience which are chosen.

But can we admit this? Are there really only reasons of con-
venience? It is not rather a matter of where the particular statements
come from, what is their origin, their history? In general, what is
meant here by convenience? What is the end that one pursues in mak-
ing and selecting statements?

The end can be no other than that of science itself, namely, that
of affording a true description of the facts. For us it is self-evident that
the problem of the basis of knowledge is nothing other than the ques-
tion of the criterion of truth. Surely the reason for bringing in the
term “protocol statement” in the first place was that it should
serve to mark out certain statements by the truth of which the truth
of all other statements comes to be measured, as by a measuring
rod. But according to the viewpoint just described this measuring rod
would have shown itself to be as relative as, say, all the measuring
rods of physics. And it is this view with its consequences that has
been commended as the banishing of the last remnant of “abso-
lutism” from philosophy.^

But what then remains at all as a criterion of truth? Since the
proposal is not that all scientific assertions must accord with certain
definite protocol statements, but rather that all statements shall ac-
cord with one another, with the result that every single one is consid-

3. K. Popper as quoted by Carnap, op. cit., Erkenntnis, Vol. Ill, p. 223.

4. Carnap, op. cit., p. 228.

MORITZ SCHLICK

[214]

ered as, in principle, corrigible, truth can consist only in a mutual
agreement of statements,

in

This view, which has been expressly formulated and represented
in this context, for example, by Neurath, is well known from the
history of recent philosophy. In England it is usually called the
“coherence theory of truth,” and contrasted with the older “corre-
spondence theory.” It is to be observed that the expression “theory”
is quite inappropriate. For observations on the nature of truth have
a quite different character from scientific theories, which always
consist of a system of hypotheses.

The contrast between the two views is generally expressed as
follows: according to the traditional one, the truth of a statement
consists in its agreement with the facts, while according to the other,
the coherence theory, it consists in its agreement with the system
of other statements.

I shall not in general pursue the question here whether the latter
view can not also be interpreted in a way that draws attention
to something quite correct (namely, to the fact that in a quite
definite sense we cannot “go beyond language” as Wittgenstein
puts it). I have here rather to show that, on the interpretation re-
quired in the present context, it is quite untenable.

If the truth of a statement is to consist in its coherence or agree-
ment with the other statements, one must be clear as to what one
understands by “agreement,” and which statements are meant by
“other.”

The first point can be settled easily. Since it cannot be meant
that the statement to be tested asserts the same thing as the others,
it remains only that they must be compatible with it, that is. that no
contradictions exist between them. Truth would consist simply in
absence of contradiction. But on the question whether truth can
be identified simply with the absence of contradiction, there ought
to be no further discussion. It should long since have been gen-
erally acknowledged that only in the case of statements of a tauto-
logical nature are truth (if one will apply this term at all) and
absence of contradiction to be equated, as for instance with the
statements of pure geometry. But with such statements every con-
nection with reality is purposely dissolved; they are only formulas
within a determinate c^culus; it makes no sense in the case of the
statements of pure geometry to ask whether they agree with the
facts of the world: they need only be compatible with the axioms

The Foundation of Knowledge [ ]

"arbitrarily laid down at the begmning (in addition, it is usually
also required that they follow from them) in order to be called true
or correct. We have before ns precisely what was earlier called
formal truth and distinguished from material truth.

The latter is the truth of synthetic statements, assertions of
matters of fact, and if one wishes to describe them by help of the
concept of absence of contradiction, of agreement with other state-
ments, one can do so only if one says that they may not contra-
dict very special statements, namely just those that express “facts
of immediate observation.” The criterion of truth cannot be com-
patibility with any statements whatever, but agreement is required
with certain exceptional statements which are not chosen arbitrarily at
all. In other words, the criterion of absence of contradiction does not
by itself suffice for material truth. It is, rather, entirely a matter of
compatibility with very special peculiar statements. And for this com-
patibility there is no reason not to use — ^indeed I consider there is
every justification for using — the good old expression “agreement
with reality.”

The astounding error of the “coherence theory” can be explained
only by the fact that its defenders and expositors were thinking only
of such statements as actually occur in science, and took them as
their only examples. Under these conditions the relation of non-
contradiction was in fact sufficient, but only because these state-
ments are of a very special character. They have, that is, in a certain
sense (to be explained presently) their “origin” in observation
statements, they derive, as one may confidently say in the traditional
way of speaking, “from experience.”

If one is to take coherence seriously as a general criterion of
truth, then one must consider arbitraiy fairy stories to be as true as a
historical report, or as statements in a textbook of chemistry, provided
the story is constructed in such a way that no contradiction ever arises.
I can depict by help of fantasy a grotesque world full of bizarre
adventures : the coherence philosopher must believe in the truth
of my account provided only I take care of the mutual compatibility of
my statements, and also take the precaution of avoiding any collision
with the usual description of the world, by placing the scene of my
story on a distant star, where no observation is possible. Indeed,
strictly speaking, I don’t even require this precaution; I can just as
well demand that the others have to adapt themselves to my descrip-
tion; and not the other way round. They cannot then object that,
say, thiy^ happening runs counter to the observations, for according

MORITZ SCHLICK

[ 216 ]

to the coherence theory there is no question of observations, but only
of the compatibility of statements.

Since no one dreams of holding the statements of a story book
true and those of a text of physics false, the coherence view fails
utterly. Something more, that is, must be added to coherence, namely,
a principle in terms of which the compatibility is to be established,
and this would alone then be the actud criterion.

If I am given a set of statements, among which are found some
that contradict each other, I can establish consistency in a number of
ways, by, for example, on one occasion selecting certain statements
and abandoning or altering them and on another occasion doing
the same with the other statements that contradict the jfirst.

Thus the coherence theory is showm to be logically impossible;
it fails altogether to give an unambiguous criterion of truth, for by
means of it I can arrive at any number of consistent systems of state-
ments which are incompatible with one another.

The only way to avoid this absurdity is not to allow any state-
ments whatever to be abandoned or altered, but rather to specify
tihose that are to be maintained, to which the remainder have to be
accommodated.

IV

The coherence theory is thus disposed of, and We have in the
meantime arrived at the second point of our criiical considerations,
namely, at the question w^hether all statements are corrigible, or
whether there are also those that cannot be shaken. These latter
would of course constitute the "‘basis” of all knowledge which w^e
have been seeking, without so far being able to take any step to-
wards it.

By what mark, then, are we to distinguish these statements
which themselves remain unaltered, while all others must be brought
into agreement with them? We shall in what follows call them not
“protocol statements,” but “basic statements” for it is quite dubious
whether they occur at all among the protocols of science.

The most obvious recourse would doubtless be to find the rule
for which we are searching in some kind of economy principle,
namely, to say: we are to choose those as basic statements whose
retention requires a minimum of alteration in the whole system of
statements in order to rid it of all contradictions.

It is worth noticing that such an economy principle would not
enable us to pick out certain statements as being basic once and
for all, for it might happen that with the progress of science the

The Foundation of Knowledge [211 \

basic statements that served as such up to a given moment would
be again degraded, if it appeared more economical to abandon them
in favor of newly found statements which from that time on —
until further notice — ^would play the basic role. This would, of course,
no longer be the pure coherence viewpoint, but one based on econ-
omy; “relativity,” however, would characterize it also.

There seems to me no question but that the representatives of the
view we have been criticizing did in fact take the economy principle
as their guiding light, whether explicitly or implicitly; I have therefore
already assumed above that on the relativity view there are pur-
posive grounds which determine the selection of protocol statements,
and I asked: Can we admit this?

I now answer this question in the negative. It is in fact not
economic purposiveness but quite other characteristics which dis-
tinguish the genuine basic statements.

The procedure for choosing these statements would be called
economic if it consisted say in conforming to the opinions (or “proto-
col statements”) of the majority of investigators. Now it is of course
the case that we do not doubt the existence of a fact, for example a
fact of geography or history, or even of a natural law, when we
find that in the relevant contexts its existence is very frequently
reported. It does not occur to us in those cases to wish to in-
vestigate the matter ourselves. We acquiesce in what is universally
acknowledged. But this is explained by the fact that we have pre-
cise knowledge of the manner in which such factual statements tend
to be made, and that this manner wins our confidence; it is not
that it agrees with the view of the majority. Quite the contrary,
it could only arrive at universal acceptance because everyone feels
the same confidence. Whether and to what extent w'^e hold a state-
ment to be corrigible or amiulabie depends solely on its origin, and
(apart from veiy' special cases) not at all upon whether mamtaining
it requires the correction of very many other statements and per-
haps a reorganization of the whole system of knowledge.

Before one can apply the principle of economy one must know
to which statements it is to be applied. And if the principle were
the only decisive rule the answer could only be: to all that are
asserted with any claim to validity or have ever been so asserted.
Indeed, the phrase “with any claim to validity” should be omitted,
for how^ should we distinguish such statements from those which were
asserted quite arbitrarily, as jokes or with intent to deceive? This
distinction cannot even be formulated without taking into considera-

[ 218 ] MORITZ SCHLICK

tion the derivation of the statements. So we find ourselves once more
referred to the question of their origin. Without having classified
statements according to their origin, any application of the economy
principle of agreement would be quite absurd. But once one has ex-
amined the statements with respect to their origin it becomes im-
mediately obvious that one has thereby already ordered them in
terms of their validity, and that there is no place left for the appli-
cation of the principle of economy (apart from certain veiy special
cases in still unfinished areas of science). We can see also that the
establishment of this order points the way to the basis of which we
are in search.

V

Here of course the greatest care is necessaiy’. For we are tread-
ing on the path which has been followed from ancient times by all
those who have ever embarked upon the journey towards the ultimate
grounds of truth. And always they have failed to reach the goal.
In the ordering of statements according to their origin which I un-
dertake for the purpose of judging their certainty, I start by assigning
a special place to those that I make myself. And here a secondary
position is occupied by those that lie in the past, for we believe
that their certainty can be impaired by “errors of memor}^” — and
indeed in genera] the more so the farther back in time they lie. On
the other hand, the statements which stand at the top, free from all
doubt, are those that express facts of one’s own “perception,” or
whatever you like to call it. But in spite of the fact that statements
of this sort seem so simple and clear, philosophers have found them-
selves in a hopeless labyrinth the moment they actually attempted
to use them as the foundation of all knowledge. Some puzzling sec-
tions of this labyrinth are for example those formulations and deduc-
tions that have occupied the center of so many philosophical disputes
under the heading “evidence of inner perception,” “solipsism,” “so-
lipsism of the present moment,” “self-conscious certainty,” etc.
The Cartesian cogito ergo sum is the best-known of the destinations
to which this path has led — a terminating point to which indeed
Augustine had already pushed through. And concerning cogito
ergo sum our eyes have today been sufficiently opened: we know
that it is a mere pseudo-statement, which does not become genuine
by being expressed in the form '"cogitatio esf — “the contents of
consciousness exist.”^ Such a statement, which does not express
anything itself, cannot in any sense serve as the basis of anything.

5. Cf. “Positivismus und Realismus,” Erkenntnis, Vol. Ill, p. 20 (see the present
volume, p. 82 above) .

The Foundation of Knowledge [ 219 ]

It is not itself a cognition, and none rests upon it. It cannot lend
certainty to any cognition.

There exists therefore the greatest danger that in following the
path recommended one will arrive at empty verbiage instead of the
basis one seeks. The critical theory of protocol statements origi-
nated indeed in the wish to avoid this danger. But the way out
proposed by it is unsatisfactor}''. Its essential deficiency lies in ig-
noring the different rank of statements, which expresses itself most
clearly in the fact that for the system of science which one takes
to be the “right” one, one’s own statements in the end play the
only decisive role.

It would be theoretically conceivable that my own observations
in no way substantiate the assertions made about the world by
other men. It might be that all the books that I read, all the teachers
that I hear are in perfect agreement among themselves, that they never
contradict one another, but that they are simply incompatible with
a large part of my own obseiv^ation statements. (Certain difficulties
would in this case accompany the problem of learning the language
and its use in communication, but they can be removed by means
of certain assumptions concerning the place in which the contra-
dictions are to appear.) According to the view we have been criticiz-
ing I would in such a case simply have to sacrifice my own “protocol
statements,” for they would be opposed by the overwhelming mass
of other statements which would be in mutual agreement themselves,
and it would be impossible to expect that these should be corrected
in accordance with my own limited fragmentary^ experience.

But what wnuid actually happen in such a case? Well, under no
circumstances would I abandon my own observation statements.
On the contrary, I find that I can accept only a system of knowledge
into which they fit unmutilated. And I can always construct such
a system. I need only view^ the others as dreaming fools, in whose
madness lies a remarkable method, or — ^to express it more ob-
jectively — I would say that the others live in a different world from
mine, which has just so much in common with mine as to make it
possible to achieve understanding by means of the same language.
In any case no matter what world picture I construct, I would test
its truth always in terms of my own experience. I would never per-
mit anyone to take this support from me: my own observation
statements would ahvays be the ultimate criterion. I should, so to
speak, exclaim “What I see, I see!”

[220 ]

MORITZ SCHLICK

VI

In the light of these preliminary critical remarks, it is clear where
we have to look for the solution of these confusing difficulties: we
must use the Cartesian road in so far as it is good and passable,
but then be careful to avoid falling into the cogito ergo sum and
related nonsense. We effect this by making clear to ourselves the
role which really belongs to the statements expressing ‘‘the immedi-
ately observed.”

What actually lies behind one’s saying that they are “absolutely
certain”? And in what sense may one describe them as the ultimate
ground of all knowledge?

Let us consider the second question first. If we imagine that
I at once recorded every observation — and it is in principle indif-
ferent whether this is done on paper or in memorv’ — and then began
from that point the construction of science, I should have before
me genuine “protocol statements” which stood temporally at the
beginning of knowledge. From them would gradually arise the rest
of the statements of science, by means of the process called “induc-
tion,” which consists in nothing else than that I am stimulated
or induced by the protocol statements to establish tentative generali-
zations (hypotheses), from which those first statements, but also
an endless number of others, follow logically. If now these others
express the same as is expressed by later observation statements that
are obtained under quite definite conditions which are exactly speci-
fiable beforehand, then the hypotheses are considered to be confirmed
so long as no observation statements appear that stand in contradic-
tion to the statements derived from the hypotheses and thus to the
hypotheses themselves. So long as this does not occur we believe our-
selves to have hit correctly upon a law^ of nature. Induction is thus
nothing but methodically conducted guessing, a psychological, bio-
logical process whose conduct has certainly nothing to do with “logic.”

In ffiis way the actual procedure of science is described schemati-
cally. It is evident what role is played in it by the statements con-
cerning what is “immediately perceived.” They are not identical
with those written down or memorized, with what can correctly be
called “protocol statements,” but they are the occasions of their
formation. The protocol statements observed in a book or memory
are, as we acknowledged long ago, so far as their validity goes,
doubtless to be compared to hypotheses. For, when we have such a
statement before us, it is a mere assumption that it is true, that it

The Foundation of Knowledge [221 ]

agrees with the observation statements that give rise to it, (Indeed
it may have been occasioned by no obsen’ation statements, but
derived from some game or other.) What I call an observation state-
ment cannot be identical with a genuine protocol statement, if
only because in a certain sense it cannot be v^Titten down at all —
a point which we shall presently discuss.

Thus in the schema of the building up of knowledge that I have
described, the part played by observation statements is first that of
standing temporally at the beginning of the whole process, stimulating
it and setting it going. How much of their content enters into
knowledge remains in principle at first undetermined. One can thus
with some justice see in the observation statements the ultimate
origin of all knowledge. But should they be described as the basis,
as the ultimate certain ground? This can hardly be maintained, for
this “origin” stands in a too questionable relation to the edifice of
knowledge. But in addition we have conceived of the true process
as schematically simplified. In reality whai is actually expressed in
protocols stands in a less close connection wiih the observed, and in
general one ought not to assume that any pure observation statements
ever slip in between the observation and the “protocol.”

But now a second function appears to belong to these statements
about the immediately perceived, these “confirmations”* as we may
also can them, namely, the corroboration of hypotheses, their verifi-
cation.

Science makes prophecies that are tested by “experience.” Its
essential function consists in making predictions. It says, for ex-
ample: “If at such and such a time you look through a telescope
adjusted in such and such a manner you will see a point of light
(a star) in coincidence with a black mark (cross wires).” Let us
assume that in following out these instructions the predicted ex-
perience actually occurs. This means that ^ve make an anticipated

* The term used by the author is ‘'tConstatierung'* which he sometimes equates
with “observation statement’* i.e., “Beobachiungssatz,” and generally tends to
quote, in a manner indicating his awareness that it is a somewhat unusuil usage and
perhaps a not altogether adequate technical term. Wilfred Sellars in a recently
published essay (“Empiricism and the Philosophy of Mind,” Minnesota Studies in
the Philosophy of Science, Volume I, Universit>- of Minnesota Press, 1956) uses the
term “report” in referring to what seems to be the kind of statement Schlick is
discussing. I do not adopt this term, despite some undoubted advantages it has
over “confirmation,” because of the close connection mat “Konstatierung” has with
confirmation or verification, a connection so close tha: Schlick uses the same term
unquoted to refer to confirmation. Furthermore, as the text shows, confirmations
are never false, as Schlick understands them; but this is certainly not a characteristic
of reports, as the term “report” is used in everyday or even scientific language.
(Translator’s note.)

[ 222 ]

MORITZ SCHLICK

^ ^ expected judgment of observation,

isfflrHr>r,° ^ feeling of fulfilment, a quite characteristic sat-

onnfi “• satisfied. One is fully justified in saying that the

sio?^^ observation statements have fulfilled their true mis-

soon as we obtain this peculiar satisfaction.

talrec moment in which the confirmation

the iu^r.ct • ™ observation statement is made. This is of

the imm function of the statements about

expenenced itself lies in the immediate present.

moment duration, that the

scrintio ‘^^sposa! in their place in-

tenable ctrLl ^ ultimate certainty. One cannot build any logically
mnrr, ructure upon the confirmations, for they are gone the
the nloce^T construct. If they stand at the beginning of

logically of no use. Quite other-

also fakifirar verification (or

renre th ^ completion, and in the moment of their occur-

hepends already fulfiUed their duty. Logically nothing more

StitUtt M °b?oiute“d”'’°‘“‘°“ ““

cnijf- Psyciiologically and biologicaliv a new process' of

S'vLfiS“ ''“5 •'■‘S' “«“■

formi.i m them are considered to be upheld, and the

searr'h V°° general hypotheses is sought, the guessing and

sSl Z The observation statements con-

in thsa “ ° Stimuli for these events that follow in time

m the sense described earlier.

cle 1 ^^^«h^•^ means of these considerations a new and

edoe problem of the ultimate basis of knowl-

edge’ tal-P-c, clearly how the construction of the system of knowl-
®p l^es place and what role the “confirmations” play in it.
tn fi ®^bon is originally a means in the service of life. In order
event? environment and to adjust his actions to

tent Fn foresee these events to a certain ex-

and h^ ^ this he makes use of universal statements, cognitions,

TPmp- occurs. Now in science this character of cognition

wholly ^

the hfc> Is not sought because of its utility. With

inu • of prediction the scientific goal is achieved: the

J y m cognition is the joy of verification, the triumphant feeling of

The Foundation of Knowledge [ 223]

having guessed correctly. And it is this that the observation state-
ments bring about. In them science as it were achieves its goal: it
is for their sake that it exists. The question hidden behind the prob-
lem of the absolutely certain basis of knowledge is, as it were, that
of the legitimacy of this satisfaction with which verification fills us.
Have our predictions actually come true? In every single case of
verification or falsification a “confirmation” answers imambiguously
with a yes or a no, with joy of fulfilment or disappointment The
confirmations are final.

Finality is a very fitting word to characterize the function of
observation statements. They are an absolute end. In them the task
of cognition at this point is fulfilled. That a new^ task begins with
the pleasure in which they culminate, and with the h}TX)theses that
they leave behind does not concern them. Science does not rest upon
them but leads to them, and they indicate that it has led correctly.
They are really the absolute fixed points; it gives us joy to reach
them, even if we cannot stand upon them.

VII

In what does this fixity consist? This brings us to the question
we postponed earlier: in what sense can one speak of observation
statements as being “absolutely certain”?

I should like to thrown light on this by first saying something about
a quite different kind of statement, namely about analytic statements.

I will then compare these to the “confirmations.” In the case of
analytic statements it is well known that the question of their
validity constitutes no problem. They hold c priori; one cannot
and should not tiy to look to experience for proof of their correctness
for they say nothing whatever about objects of experience. For this
reason only “formal truth” pertains to them, i.e., they are not “true”
because they correctly express some fact. What makes them true is
just their being correctly constructed, i.e. their standing in agreement
with our arbitrarily established definitions.

However, certain philosophical writers have thought themselves
obliged to ask: Yes, but how do I know^ in an individual case whether
a statement really stands in agreement with the definition, whether
it is really analytic and therefore holds without question? Must I
not carry in my head these definitions, the meaning of all the words
that are used when I speak or hear or read the statement even if it en-
dures only for a second? But can I be sure that my psychological ca-
pacities sufifice for this? Is it not possible, for example, that at the end

[ 224 ] MORITZ SCHLICK

of the statement I should have forgotten or incorrectly remembered
the beginning? Must I not thus agree that for psychological reasons I
can never be sure of the validity of an analytic judgment also?

To this there is the following answer: the possibility of a failure
of the psychic mechanism must of course always be granted, but the
consequences that follow from it are not correctly described in the
sceptical questions just raised.

It can be that owing to a weakness of memory, and a thousand
other causes, we do not understand a statement, or imderstand it
erroneously (i.e. differently from the way it was intended) — ^but what
does this signify? Well, so long as I have not understood a sentence
it is not a statement at all for me, but a mere series of words, of
sounds or written signs. In this case there is no problem, for only
of a statement, not of an uncomprehended series of words, can
one ask whether it is analytic or synthetic. But if I have misinter-
preted a series of words, but nevertheless interpreted it as a state-
ment, then I know of just this statement whether it is analytic or
synthetic and therefore valid a priori or not. One may not sup-
pose that I could comprehend a statement as such and still be in
doubt concerning its analytic character. For if it is anaMic 1 have
understood it only when I have understood it as analytic. To under-
stand means nothing else, that is, than to be clear about the rules
governing the use of the words in question; but it is precisely these
rules of usage that malce statements analytic. If I do not know
whether a complex of words constitutes an anai}1;ic statement or not,
this simply means that at that moment I lack the rules of usage: that
therefore I have simply not understood the statement. Thus the
case is that either I have understood nothing at all, and then noth-
ing more is to be said, or I know whether the statement which I under-
stand is synthetic or analytic (w^hich of course does not presuppose
that these words hover before me, that I am even acquainted with
them). In the case of an analytic statement I know at one and the
same time that it is valid, that formal truth belongs to it.

The above doubt concerning the validity of analytic statements
was therefore out of order. I may indeed doubt whether I have
correctly grasped the meaning of some complex of signs, in fact
whether I shall ever understand the meaning of any sequence of
words. But I cannot raise the question whether I can ascertain the
correctness of an analytic statement. For to understand its meaning
and to note its a priori validity are in an analytic statement one
and the same process. In contrast, a synthetic assertion is charac-
terized by the fact that I do not in the least know whether it is

The Foundation of Knowledge [ 225 ]

true or false if I have only ascertained its meaning. Its truth is
determined only by comparison with experience. The process of
grasping the meaning is here quite distinct from the process of
verification.

There is but one exception to this. And we thus return to our
"‘confirmations.’" These, that is, are always of the form “Here now
so and so,” for example “Here two black points coincide,” or “Here
yellow borders on blue,” or also “Here now pain,” etc. What is
common to all these assertions is that demonstrative terms occur in
them which have the sense of a present gesture, i.e. their rules of usage
provide that in making the statements in which they occur some
experience is had, the attention is directed upon something ob-
served. What is referred to by such words as “here,” “now,” “this
here,” cannot be communicated by means of general definitions in
words, but only by means of them together with pointings or ges-
tures. “This here” has meaning only in connection with a gesture.
In order therefore to understand the meaning of such an observa-
tion statement one must simultaneously execute the gesture, one
must somehow point to reality.

In other words: I can understand the meaning of a “confirma-
tion” only by, and when, comparing it with the facts, thus carr^mg
out that process which is necessary for the verification of all syn-
thetic statements. While in the case of all other synthetic statements
determining the meaning is separate from, distinguishable from,
determining the truth, in the case of obsen'ation statements they
coincide, just as in the case of analytic statements. However difier-
ent therefore “confirmations” are from analytic statements, they have
in common that the occasion of understanding them is at the same
time that of verifying them: I grasp their meaning at the same time
as I grasp their truth. In the case of a confirmation it makes as
little sense to ask whether I might be deceived regarding its truth
as in the case of a tautology. Both are absolutely valid. However,
while the analytic, tautological, statement is empty of content, the
observation statement supplies us with the satisfaction of genuine
knowledge of reality.

It has become clear, we may hope, that here everything depends
on the characteristic of immediacy which is peculiar to observ’'ation
statements and to which they owe their value and disvaiue; the value
of absolute validity, and the disvaiue of uselessness as an abiding
foundation.

A misunderstanding of this nature is responsible for most of
the unhappy problems of protocol statements with which our en-

[ 226 ] MORITZ SCHLICK

quity began. If I make the confirmation “Here now bine,” this
is not the same as the protocol statement “M. S. perceived blue
on the nth of April 1934 at such and such a time and such
and such a place.” The latter statement is a hypothesis and as such
always characterized by uncertainty The latter statement is equiva-
lent to “M. S. made . . . (here time and place are to be given)
Ae confirmation ‘here now blue.’ ” And that this assertion is not
identical with the confirmation occurring in it is clear. In protocol
statements there is always mention of perceptions (or they are to
be added in thought — the identity of the {>erceiving observer is im-
portant for a scientific protocol), while they are never mentioned in
confirmations. A genuine confirmation cannot be written down, for
as soon as I inscribe the demonstratives “here,” “now,” they lose
their meaning. Neither can they be replaced by an indication of
time and place, for as soon as one attempts to do this, the result,
as we saw, is that one unavoidably substitutes for the observation
statement a protocol statement which as such has a wholly different
nature.

VIII

I believe that the problem of the basis of knowledge is now
clarified.

If science is taken to be a system of statements' in which one’s
interest as a logician is confined to their logical connections, the ques-
tion of its basis, which would then be a ‘logical” question, can be
answered quite arbitrarily. For one is free to'define the basis as one
wishes. In an abstract system of statements there is no priority and
no posteriority. For instance, the most general statements of science,
thus those that are normally selected as axioms, could be regarded
as its ultimate foundation; but this name could just as well be re-
served for the most particular statements, which would then more
or less actually correspond to the protocols written down. Or any
other choice would be possible. But all the statements of science are
collectively and individually hypotheses the moment one considers
them from the point of view of their truth value, their validity.

If attention is directed upon the relation of science to reality
the system of its statements is seen to be that which it really is,
namely, a means of finding one’s way among the facts; of arriv-
ing at the joy of confirmation, the feeling of finality. The problem
of the “basis” changes then automatically into that of the unshakeable
point of contact between knowledge and reality. We have come to
know these absolutely fixed points of contact, the confirmations, in

The Foundation of Knowledge [ 227 ]

their individuality: they are the only synthetic statements that are not
hypotheses. They do not in any way He at the base of science; but
lie a flame, cognition, as it were, Hcks out to them, reaching each
but for a moment and then at once consuming it. And newly fed
and strengthened, it flames onward to the next.

These moments of fulfilment and combustion are what is essen-
tial All the light of knowledge comes from them. And it is for the
source of this Hght the philosopher is really inquiring when he seeks
the ultimate basis of all knowledge.

Verification and Experience

BY A. J. AYER

What IS it that determines the truth or falsehood of empirical
propositions? The customary answer is, in effect, that it is their
agreement or disagreement with reality. I say “in effect” because I
■ftis to allow for alternative formulations. There are some who
would speak of correspondence or accordance rather than agree-
ment, some^who for the word “reality” would substitute “facts” or
expenrace.” But I do not think that the choice of different words
h T important difference of meaning. This answer,

\Tiriv if to be correct, requires some elucidation. To

quo e Willia m James; “Pragmatists and InteUectualists both accept
y ; as a matter of course. They begin to quarrel only after the ques-
lon is raised as to what precisely may be meant by the term ‘agree-
men and what by the term ‘reality’ when reality is taken as some-
1- hf to agree with.”^ I hope at least to throw some

ngnt upon tMs question in the course of this paper.

t simplify our undertaking if we can draw a distinction be-
ween mose empirical propositions whose truth or falsehood can be
etermined only by ascertaining the truth or falsehood of other
propositions and those whose truth or falsehood can be determined
directly by observation. To the former class belong all universal
propositmns. We cannot, for example, directly establish the truth or
lalsehood of the proposition that gold is dissoluble in aqua regia,
unless of wurse we regard this as a defining attribute of gold and
so make the proposition into a tautology. We test it by estabhshing
me truth or falsehood of singular propositions relating, among other
mmgs, to p articular pieces of gold. We may indeed deduce one uni-

published in the Proceedings of the Aristotelian Society,
the Aristotelian Society * “ reprinted here with the permission of the secretary of

1. Pragmatism, p. 198.

Verification and Experience [ 229 ]

versal proposition from another, or even infer it by analogy, but
In all such cases we must finally arrive at a proposition for which
the evidence consists solely in the truth or falsehood of certain
singular propositions. It is here to be remarked that no matter how
many such singular propositions we succeed in establishing we are
never entitled to regard the universal proposition as conclusively
verified. However often we may have observed the dissolution of
pieces of gold in aqua regia, we must still allow it to be possible that
the next piece with which we experiment will not so dissolve. On
the other hand the falsity of any one of the relevant singular propo-
sitions does entail the falsity of the universal proposition. It is this
logical assymetiy in the relationship of universal and singular prop-
ositions that has led some philosophers^ to adopt the possibility of
falsification rather than that of verification as their criterion of em-
pirical significance.

We said that the way to test the validity of a universal proposi-
tion about the dissolubility of gold was to ascertain the truth or
falsehood of singular propositions referring to particular pieces of
gold. But these propositions in their turn depend for their verification
upon the verification of other propositions. For a piece of gold is a
material thing; and to test the validity of propositions referring to
material things we must ascertain the truth or falsehood of propo-
sitions referring to sense-data. Here we have another instance of
logical assymetr>\ A proposition referring to a material thing may
entail propositions referring to sense-data but cannot itself be en-
tailed by any finite number of them.

Now at last we seem to have reached propositions which need
not wait upon other propositions for the determination of their truth
or falsehood, but are such that they can be directly confronted with
the given facts. These propositions I propose to call basic proposi-
tions. If the distinction which we have drawn between them and
other propositions is legitimate, we may confine ourselves, for our
present purpose, to questions concerning the nature of basic prop-
ositions and the manner in which our determination of their validity
depends upon our experience.

It is noteworthy that the legitimacy of the distinction which we
have drawn is implicitly acknowledged even by philosophers who re-
ject the notion of agreement with reality as a criterion of truth.
Neurath and Hempel, for example, have recently been maintaining
that it is nonsensical to speak of comparing propositions with facts

2. Notably Karl Popper. See his Logik der F orschung^

f 'j'2a "

A. J. AYER

r 230 1 ^tjosition, they say, can be compared

1 -,, o-merience.® A * t the same time they assign a status
‘A ^^nther proposition' -jc propositions to a class of propo-
only with another|^^l^^ t^f^roposLns. According to NeuraA,

corresponding to otoc^l ? 1 jtion it is necessary that

sitions whch they ^ pf^^^scription of an observer and some

for a sentence W or Nervation. He gives the following as

It should cont^ 3.17/Otto’s speech-thought at

words refe^g W protocol 3 ^5 ^ observed by

^ examp ®- in tb® . y Neurath as the only legitimate w'ay

Otto 17^11^3 is cot regarded position. If others care to adopt a
f ? ' , „ a protocol P^^ as far as he is concerned, at hberty

of fonnulatmg a F P chosen

“ .'S' brclaims'for protocol propositions greater

hHays this. He is thinking of
stab^ty than „gh to so® .J^^Otto hi been having a hallucma-
is . jt turns out a to be lying. In the former case the

Je case m w^^ to be false; in the

tion or that m wtt bracket. But the whole proposi-

proposidon “ tbc ^ propositions within the brackets,

after, the pro^ ^Jfunctioi of one another. We may

tion IS not a t^^^^ trtrt^_ven when we have rdjected them. In
my more . ^ to accept is surely inconsistent with Neurath s

therefore contm^ Bbt/^re debired from appealing to the

Itself, this is a vau^ ^ hallucination?

mam position. ^ discover tb^ falsehood of any proposition whatso-
facts, we e or incompatibility with other

Neurath m^es compel other criterion. In this respect, his

ever de^nd up b any advantage. If we are

proposihons. ^ .^^tis are i^^^tjosition and also with a non-protocol
protocol propositi not obliged to

presented with a P the other. We have an

proposition wlu^ proposit»^t if this is so we need not bother to
accept the Ptot^ ^ propositions in order to ensure

equal nght to for pff^ do if we wish a proposition to be

detnse ^ we have \ and to reject any proposition that is

then stabihty. accept -gtion whether such a decision is em-

stable IS to decio®

incomDatible ^ ‘ ** Erkenntnis, Volume III, p. 223, [see

mcompatlD ie WX ‘Wirkliche writ.-” Erkennmis. Vol IV;

3. Otto Neuratb, ‘ ^ Theory of Truth,;’ .4mily«r, Vol II

p. 199], and “RadiK^®^ Lo^c^ F'^’^no/yrir, Voi. Ill, and Some Remarks
Carl Hempel, “On. ]g; 333 piricism**

“Some Remarks o^. ^ « Analysi^^

Tacts’ and Proposit^^

Verification ana i^^xperienut:

piiically justified or not is one to which, according to the implications
of Nenrath’s doctrine, no meaning can be attached.

One wonders indeed why he and Hempel pay so much attention
to protocol propositions, inasmuch as the only distinction which they
are able to draw between them and other propositions is a distinction
of form. They do not mean by a protocol proposition one which can
be directly verified by observation, for they deny that this is possible.
They use the term “protocoF’ purely as a S5mtactical designation for
a certain assemblage of words. But why should one attach special
significance to the word “observation”? It may be that there is no
error involved in constructing sentences of a peculiar type and dig-
nifying them with the title of Protokollsdtze, but it is arbitrary and
misleading. There is no more justification for it than there would be
for making a collection of all the propositions that could be cor-
rectly expressed in English by sentences beginning with the letter
B, and choosing to call them Basic propositions. If Neurath and
Hempel do not recognize this it is probably because, in writing
about Frotokollsdtze, they unconsciously employ the forbidden cri-
terion of agreement with experience. Though they say that the term
‘"protocol” is nothing more than a syntactical designation, they do
not use it merely as such. We shall see later on that Carnap equivo-
cates with this term in a similar w^ay.

It is not, however, a sufficient reason for rejecting a theory that
some of its advocates have failed consistently to adhere to it. And
it is necessary for us to investigate more closely the view that in
order to determine the validity of a system of empirical propositions
one cannot and need not go beyond the system itself. For if this
view were satisfactory we should be absolved from troubling any
further about the use of the phrase “agreement v/ith experience.”

The theory which we now have to examine is that wfiich is com-
monly known as the coherence theory of truth. It should be noted
that the theoiy^ is not, as we interpret it, concerned w'ith the definition
of truth and falsehood but only with the means by which they are
determined. According to it a proposition is to be accepted if it is
found to be compatible with other accepted propositions, rejected
if it is not. If, however, we are anxious to accept a proposition which
conflicts with our current system we may abandon one or more of
the propositions which we had previously accepted. In such a case
we should, it is sometimes said, be guided by a principle of economy.
We should make the smallest transformation of the system which
ensured self-consistency. I think it is usually assumed also that we
have, or ought to have, a preference for large and highly integrated

A. J. AYER

[ 232 ]

systems; systems containing a great number of propositions which

suDDort one another to a high degree.

One strong objection to this theory is well put by Professor
Price in his lecture on Truth and Corrigibility. “Suppose,” he says,
“we have a groi^P of mutually supporting judgments. The extraor-
dinary thin«’ is that however large the group may be, and however
vreat the support which the members give to each other, the entire
arniin hanes, SO to speak, in the air. If we accept one member, no
dnnht it will he reasonable to accept the rest. But why must we
anv of them? Why should we not reject the whole lot? Might
thev^not all be false, although they all support each other?”^ He
c^oes on to argue that we cannot consider such a system of judgments
to have even'anv probability unless we can attribute to at least one
of if<; constituents a probability which is derived from some other
j than its membership of the system. He suggests therefore
f-L.^ „n}y way to save the theory would be to maintain that some
oronositions were intrinsically probable. But tins, though he does
^ i so. is reduce it to absurdity. There is no case at ^ to
. jp Qut for the view that a proposition can be probable inde-
^nXntlv of all evidence. The most that could be said in favor of
^vone w’ho accepted Price's suggestion would be that he had chosen
the word “probabUity'” an unfamiliar sense. _ __

^ -jjt w'hich Price appears to have overlooked is that accord-
• a t one well-known version of the coherence theory there can
one completely coherent system of propositions. If this were
theory would give us at least an unequivocal criterion for
the truth of any proposition; namely, the possibility
of 'n-oi-Dorating it in this single system. It would not, however,
fr ^ rT IS anv around for supposing that the enlargement of an ap-
.onerent system of propositions increased its probability,
o ""th ^ contrary’, we ought rather to hold that it decreased it. For
° ^ thesi uny set of propositions which is intemally coherent
ex nypoi therefore, we have a set of propositions

h °aDDsars to be self-consistent, either it is the unique coherent
^ it contains a contradiction which we have failed to dis-

system or greater the probability that it con-

cover, an discover. But in saying

tarns a c g^ssuniing the truth of a proposition about the limited
^ ^ human understanding, which may or may not find a

pla^rL coherent system. Perhaps, therefore, it would be

— 4 Tru th^^^^ Corrigibility (Inaugural lecture, Oxford University Press, 1936),
D 19.

r 233 ]

Verification and Experience

better to say that the advocates of this form of the coherence theory
HJCTwnse with the notion of probability altogether.

Vt now we must ask. Why should it be assumed Aat gdy one
completely coherent system of propositions is conceivable. H
many empirical propositions we succeed m combimng mto an
pareLy self-consistent system we seem always able to
rival system which is equally extensive, appears equ^ free from
contraction, and yet is incompatible with the first
be held that at least one of these systems must contam a contra i
tion even though we are unable to detect it? I can see no reason
at ^ for this assumption. We may not be able to
a given system is free from contradiction; but tms does not me
thS it is probable that it contains one. This indeed is recoded by
the more recent advocates of what we are calhng a coherence JT-
They admit the possibility of inventing fictitious sciences and histones
which would be just as comprehensive, elegant and free -ro“ c -
tradiction as those in which we actually oeiieve. But how then do
they propose to distinguish the true systems from the false/

The answer given® is that the selection of the true system does
not depend upon any internal features of the system itseli. 1
not be effected by purely logical means. But it can be carried out
inside the realm of descriptive syntax. We are to say that the true
system is that which is based upon true protocol propositions; and
that true nrotocol propositions are those which are produceo by
accredited ‘obser^'ers, including notably the scientists of our era
Logically, it might be the case that the protocol propositions which
each of us expressed were so divergent that no common system o^
science or only a very^ meagre system could De oaseo upon them. Bdi
fortunately this is not so. People do occasionally proauce incon-
venient protocol propositions. But being in a small minonty they
are over-ridden. They are said to be bad observers or liars or, m
extreme cases, mad. It is a contingent, historical fact that the rest
of us agree in accepting an “increasingly comprehensive, co^on,
scientific system.” And it is to this, so the theory runs, that we
refer when out of the many coherent systems of science that are
conceivable we speak of only one as being true.

This is an ingenious answer; but it will not do. One reason why
we trust “the scientists of our era” is that we believe that they give
an accurate account of their observations. But this means that we
shall be involved in a circle if we say that the reason why we accept

5. E.g., by Rudolf Camap, “Erwidenmg auf die Aufsatze von E. Zilsel und
EL Dimcker,” Erkenntnis, Vol. Ill, PP- 179-180.

A. J. AYER

[ 234 ]

certain evidence is merely that it conies from the scientists of our
era. And furthermore. How are we to determine that a particular
system is accepted by contemporary scientists except by appealing
to the facts of experience? But once it is conceded that such an
appeal is possible there is no longer any need to bring in the con-
temporary scientists. However great our admiration for the achieve-
ments of the scientists of our era we can hardly maintain that it is
only with reference to their behavior that the notion of agreement
with reality has any meaning. HempeF has indeed attempted to meet
this objection by telling us that instead of saying that “the system
of protocol-statements which we call true may only be character-
ized by the historical fact that it is actually adopted by the scientists
of our culture circle” we ought to express ourselves “formally” and
say: “The following statement is sufficiently confirmed by the
protocol-statements adopted in our science; ‘Amongst the numerous
imaginable consistent sets of protocol-statements, there is in practice
exactly one which is adopted by the vast majority of instructed
scientific observers; at the same time, it is just this set which we
generally call true.’ ” But this does not remove the difficulty. For
now we must ask, How is it determined that the protocol-statements
which support the statement quoted really are adopted in our science?
If Hempei is really speaking formally, as he says he is, then the
phrase “adopted in our science” must be regarded merely as an
arbitrary syntactical designation of a certain set of sentences. But it
is clear that he does not intend it to be nothing more than this. He
intends it to convey the information that the propositions expressed
by these sentences actually are adopted. But this is to re-introduce the
reference to historical fact which he is trying to eliminate. We have
here a fallacy which is akin to the fallacy oi the ontological argu-
ment. It is not legitimate to use the phrase “adopted in our science”
simply as a means of naming certain statements and then proceed
to infer from this that these statements really are adopted in it. But
Hempei cannot dispense with this fallacious inference. For each of
many incompatible systems might contain the statement that it alone
was accepted by contemporary scientists, together with the protocol
propositions that were needed to support it.

We may conclude then that the attempt to lay down a criterion
for determining the truth of empirical propositions which does not
contain any reference to “facts” or “reality” or “experience,” has
not proved successful. It seems plausible only when it involves a
tacit introduction of that very^ principle of agreement with reality

6. Analysis, Vol. Ill, pp. 39-40.

Verification and Experience [ 235 ]

which it is designed to obviate. Accordingly, we may return to our
origmal question conceming the nature of basic propositions and
the manner in which their validity depends upon fact. And first of
aE I wish to consider how far this question admits of a purely con-
ventional answer.

According to Professor Carnap it is wholly a matter of conven-
tion what propositions we take as basic. “Every concrete proposi-
tion,” he tells us,^ “belonging to the physicalistic system-language can
in suitable circumstances serve as a protocol proposition. Let G be
a law (that is a general proposition belonging to the system lan-
guage). For the purpose of verification one must in the first instance
derive from G concrete propositions referring to particular space-
time points (through substitution of concrete values for the space-
time co-ordinates x, y, z, t which occur in G as free variables).
From these concrete propositions one may with the help of addi-
tional laws and logico-mathematical rules of inference derive further
concrete propositions, until one comes to propositions which in the
particular case in question one is willing to accept. It is here a
matter of choice which propositions are employed at any given time
as the terminating points of this reduction, that is as protocol propo-
sitions. In every case the process of reduction, which serves the
purpose of verification, must be brought to an end somewhere. But
one is never obliged to call a halt at any one point rather than
another.”

In reasoning thus, Carnap says that he is following the example
of Karl Popper. Actually Popper adopts a rather narrower conven-
tion. He proposes, and takes the view that there can in this matter
be no warrant for anything more than a proposal, that basic propo-
sitions should have the form of singular existentials. They must,
according to his convention, refer to particular spatio-temporal points
and the events which are said to be occurring at these points must
be observable events. But in case anyone should think that the use
of the word “observable” brings in an element of psychology he
hastens to add that instead of an “observable” event he might
equally well have spoken of an event of motion located in (macro-
scopic) physical bodies.® His views conceming the verification of
these propositions are summed up as follows: “The basic proposi-
tions are accepted by an act of wiE, by convention. Sie sitid Festset-
zungenf’^

7. “trber Protokollsatze.” Erkenntnis, Vol. Ill, p. 224.

8. Logik der Forschung, p. 59.

9. Op. ciL, p. 62.

C ] A. J. AYER

The verification of all other empirical propositions is held to
depend upon that of the basic propositions. So that if we take the
remark I have quoted literally, we are presented with the view that
our acceptance or rejection of any empirical proposition must be
wholly arbitrary. And this is surely wrong. Actually, I do not think
that Popper himself wishes to maintain this. His stipulation that
basic propositions should refer to observable events suggests that he
recognizes that our acceptance of them somehow depends upon our
observations. But he does not tell us how.

There is indeed this much truth in what Popper says. The prop-
ositions which he calls basic refer to material things. As such, they
can be tested by observation, but never conclusively established.
For, as we have already remarked, although they may entah propo-
sitions referring to sense-data they cannot be entailed by them. It
follows that there is in our acceptance of them an element of con-
vention. I cannot carry out all the tests which would bear upon
the truth of even so simple a proposition as that my pen is lying
on my table. In practice, therefore, I accept such a proposition after
making only a limited number of tests, perhaps only a single test,
which leaves it still possible that it is fsdse. But this is not to say
that my acceptance of it is the result of an arbitrary decision. I have
collected some evidence in favor of the proposition, even though
it may not be conclusive evidence. I might have accepted it with-
out having any evidence at aU; and then my decision would, in fact,
have been arbitrary. There is no harm in Popper's insisting that our
acceptance of such propositions as he calls basic is not wholly dic-
tated by logic; but he ought still to distinguish the cases in which
our acceptance of a “basic” proposition is reasonable from those in
which it is not. We may say that it is reasonable when the proposi-
tion is supported by our obsenmtions. But what is meant by saying
that a proposition is supported by our obsewations? This is a ques-
tion which in his discussion of the “Basis-problem” Popper does not
answer.

We find, therefore, that this “discover}'” of Popper's which has
been fastened on to by Carnap amounts to no more than this; that
the process of testing propositions referring to physical objects can
be extended as far as we choose. What is conventional is our decision
to carry it in any given case just so far and no farther. To express
this, as Carnap does, by saying that it is a matter of convention
what propositions we take as protocols is simply to give the term
“protocol proposition” an unfamiliar meaning. We understand that
he now proposes to use it to designate any singular proposition, be-

Verification and Experience [ 237 ]

longmg to '‘the physicalistic system-language,” which we are pre-
pared to accept without further tests. This is a perfectly legitimate
usage. What is not legitimate is to ignore the discrepancy between it
and his former usage according to which protocol propositions were
said to “describe directly given experience.” And in abandoning the
original usage he has incidentaliy shelved the problem which it was
designed to meet.

Elsewhere/^ Carnap has suggested that problems concerning the
nature of basic propositions, in our sense of the term, depend for
their solution only on conventions about forms of words. I think
that this, too, can be shown to be a mistake. Most people are by
now familiar with his division of propositions into factual proposi-
tions such as “the roses in my garden are red,” pseudo-factual prop-
ositions such as “a rose is a thing,” which are also said to be syntacti-
cal propositions, expressed in the material mode of speech, and
propositions such as “ ‘rose’ is a thing-word,” which are syntactical
and expressed in the formal mode of speech. Now when he raises
the question “W^hat objects are the elements of given, direct experi-
ence?” he treats it as if it were a syntactical question, expressed in
the material mode of speech. That is, he considers it to be a loose
way of raising the question “What kinds of word occur in protocol-
statements?”^^ And he sets out various possible answers both in
what he calls the material and in what he calls the formal mode.
Thus, he says that it may be the case that “the elements that are
directly given are the simplest sensations and feelings” or “more
complex objects such as partial gestalts of single sensory fields” or
that “material things are elements of the given”; and he takes these
to be misleading w^ays of saying that “protocol-statements are of
the same kind as: ‘joy now/ ‘here, now, blue’ ” or that “protocol-
statements are of forms similar to ‘red circle, now' ” or that they
have “approximately the same kind of form as ‘a red cube is on the
table.’ assumes that questions about the nature of

immediate experience are linguistic in character. And this leads him
to dismiss all the “problems of the so-called given or primitive data”
as depending only upon our choice of a form of ianguage.^^ But
this is to repeat the error of Neurath and Hempel, which we have
already exposed. If the term “protocol-statement” was being used
merely as a syntactical designation for certain combinations of

10. Logical Syntax of Language, pp. 305-6.

11. The Unity of Science, p. 45.

12. The Unity of Science, pp. 46-7.

13. The Logical Syntax of Language, pp. 305-6.

Iliil

■,,'i

[238 ]

Sd tea mS °f “> applied it

to all EngUsh sentences teJSJ Sthf BS'tht'-®”''°\“'’““”

m whicli CamaD ‘ ^ sense

iiot to mark out the fomfnf ^ ^smg the tenn. He is using it

the fact that the^refe^to statements, but rather to express

our answer to his question “Whaf ^twjrdingly,

statements?” cm SneL ^ ^ PtotoSl-

hnguistic forms. It musf denpnrt ^ conventional choice of

the question “What object^ are ^ r answer

perience?” And this is not a matt given, direct ex-
fact. It is a plain question of ffr/ °h ^

theory of sensation is correct. atomistic or the

directly given are &“^simDlest°^°^*^!°° elements that are

takes tot C^niap

of speech, is not syntacdcal a? S° “ ^^^“^^^tial mode

gives as its formal eaiiiv^ilp^nf \ proposition which he

of toe same S 2 wlr’S;'’*' >«““‘-totom=n,s are
not syntactical either If wr wnni ^ ted’ ” is

pseudo-syntactical proLition And h^tw ^ ®ay call it a

seems to be about words hut it ^ “ean that it

tant that the existenerS sn.h ™tior-

for they are q^^tfa? dan^tuT^r^^^^^ T"

propositions of which Caman ^,,7 i ^ pseudo-iactual

the source of confustn isThe ?fu" “Stance

without contradiction be Le^edtoth f

tion and as involving a ^ ^ ^ ^°tmal desiana-

is precisely bow CeL J Jn^. f ^ But this

Jed to make STmisSTnf ^i^us that he is

of basic propositions can bft-Tded meref^^h"^
indeed a matter of convention th ^ <hn f/ ft is

of the letters “j o y” to denote inv ^ consisting

is immediately experienced, which Is inToli^

d-srtSoi.’ Soix

n? “Sr^S 22 2rS ?

n..ne « priori. Wr toa; h„,d todaedZ,'’rpet‘„r2S22'S

' Verification and Experience j 239 j

always private to Mmself; but this is only because we happen so to
use words that it does not make sense to say “I am acquainted with
your sense-data” or “You and I are experiencing the same sense-
datum.”^^ This is a point about which we are apt to be confused
One says mournfully “I cannot experience your toothache” as
though It revealed a lack of mental power. That is, we are inclined
to think of the contents of another person’s mind, or the immediate
objects of his experience, as being concealed from us by some sort
of natural obstacle, and we say to ourselves: “If only we had a ray
which would penetrate this obstacle!” (Intuition!) or “Perhaps we
ran ^r^truct a reflector which will show us what is going on behind.”
But m fact there is no obstacle but our usage of words. To sav that
whatever is directly “given” to me is mine and mine only is to ex-
press a tautology. A mistake which I, for one, have made in the past
IS to co^se this with the proposition “Whatever is directly ‘given’
IS nune. This is not a tautology. It is an empirical proposition, and

A further point which it is advisable to make clear is that we
are not settmg any arbitrary boundaries to the field of possible ex-
penence. As an iUustration of this let us consider the case of the
who claims to have an immediate, non-sensory experience of

content of his experience, I have no right to disbelieve him. Not
aving such experiences inyself I cannot understand him fully. I do
not m 5 'self know what it is like to be acquainted with God. But I
S ^ rin understand Aat he is having some experience of a kind
ftat I do not have. And this I may readily beUeve. I should cer-
J’® “ assuming that the sort of experiences that I

myself had were the only sort that could be had at aU. At the same
time It must be remarked that “God,” in this usage, cannot be the
name of a transcendent bemg. For to say that one was immediately

S^thoul'^f a transcendent being would be self-contradictory*,
^d though It rnight be the name of a person who in fact endur^

Hbfl? 1- immediately acquainted with

Sbf. too, would be self^ontradicto^

wouM the fact that people were acquainted with God in
s sense, afford a valid ground for inferring that the world had a
mst cause, or that human beings survived death, or in short that
ything existed which had the attnbutes that are popularly ascribed

A. J. AYER

[ 240 ]

® experience.

KTfx \p srtainly not be justified in den3diig a priori the Dossi-

thaf^th experience. But this does not mean that we recognize

Sv? worTd^n/ ground for inferring the existence of an idealf^
of “God” or i *!, to say this because the use

kind of ^ “ a designation of the content of a certain

expenence often misleads people into thinking that they are

adi-? and we must make it clear that in

mittmg the possibility of such experiences we are not also ud
mg the conclusions which are iUegitimately drawn from them
We have tned to show that neither the form nor the vSdiW
asic propositions is dependent merely on convention Since It is
their function to describe what can be immediaS exSenid
Will depend upon the general nature of the “given ” their
St? ^g^^^^ent with it in the relevanTpaSSr ctsT

do S relation of agreement? What kind of Correspondence

It IS sometimes suggested that this relation of agreement of
Ae saine kmd as that which holds between a pttuS“S o

iSeeVS " is true. Itl ptsibCe

* construct picture-languages; no doubt they have their ad
iSfeSe- Cr thaS"? maintained that they alone are

lauguage ;ithoug^.?

&'SlhSsSSC“'‘'°CJ ^re sometimes veri-

S^doTfhf ■ rSr concerned is one of picturing. Be-

presumably false prCposTti^Tr^so^^ar^KCS^ SS

Z tht I ? r “ toat case the introduction

of the notion of picturing does not serve our purpose It does nCS
enaWe us to dispense with the notion of agreemCn?

tion nf objections hold against those who say that this rela-

tion of agreement is one of identity of stmctnrp Tt,;c v * f .

rfS’f^°“ “^P®- is to’ be supposed

a false proposition is ako a map The mer^ f^rrr, ';^“PP°s®“.tnat

wiii .0. «n .

Verification and Experience [ 241 ]

imagmaiy or real. Can we then avoid saying that we test the truth
of such a map by seeing whether it agrees with reality? But then
the notion of agreement is still left imciarified. And, in any case,
why should it be assumed that if a proposition is to describe what
is directly given it must have the same structure as the given? One
might, perhaps, allow the possibility of creating a language in which
all basic propositions were expressed by sentences functioning as
maps, though I am by no means sure that it would be possible to
draw a map of our internal sensations; but I can see no ground at all
for assuming that only a language of this kind is legitimate, or that
any of the European languages with which I am acquainted is a
language of this ]^d. Yet propositions, expressed in these languages,
are frequently verified. There is, perhaps, a historical connection
between the view that basic propositions must be identical in struc-
ture with the facts that verify them and the view that only structure
can be known or expressed.^^ But this too is arbitrary, and indeed
self-defeating. To maintain that content is inexpressible is to behave
like Ramsey's child. “ ‘Say breakfast.’ ‘Can't.’ ‘What can’t you say?’
‘Can’t say breakfast.’

What is being assumed in the theories which we have just been
discussing is not so much that a proposition cannot be verified as
that it, or, to speak more accurately, the sentence expressing it, can-
not have a sense at all unless it is a picture or a map. The difficulty
with regard to sentences that express false propositions is got round
by sa}ing that they depict or map possible facts. But surely this
assumption is quite gratuitous. If I am speaking English I may use
the words “I am angiy^” to say that I am angry. You may say, if
you like, that in doing so I am obeying a meaning-rule^'^ of the English
language. For this to be possible it is not in the least necessary that
my words should in any w'ay resemble the state of anger which they
describe. That “this is red” is used to say that this is red does not
imply that it bears any relation of resemblance, whether of structure
or content, to an actual or hypothetical red patch.

But if the words “I am angry” are used to say that I am angry,
then it does not seem in any way mysterious that my being angry
should verify the proposition that they express. But how do I know
that I am angiy? I feel it. How do I know that there is now a loud
sound? I hear it. How do I know that this is a red patch? I see it.

15. Cf. E. Ziisel, “Bemerkimgeii zur Wissenschaftslogii:,” Erkenntnis, VoL III,
p. 143.

16. Foundations of Mathematics^ p. 268. [Vide pp. 321-6 of this volume.]

17. Cf. K. Ajdukiewjcz, “Sprache und Sinn,” Erkenntnis, Vol. IV, pp. 114-116.

[ 248 ]

[242 1

A. J. AYER

If this answer is not regarded as satisfactory, I do not know what
other can be given.

It may be suggested that we ou^t in this connection to intro-
toce the notion of causation. The relation, it may be said, between
me proposition “I am in pain” and the fact that verifies it is that
me feet causes me to assert the proposition, or at any rate to believe
It. that such a relation often exists is not to be denied But we
cammt andyze verification in terms of it. For if I am a habitual liar
my bemg m pam may cause me to deny that I am in pain; and if
1 am a sufficiently hidebound Christian Scientist it may not cause
me to believe it. But in either case my being in pain wiU verify the
proposition that I am in pain. Why? Because when I say “I am in
pam I mean that I am m pain, and if p then p. But how do I estab-

c2 oLy J it IS'Z

propositions must be regarded as in-
comgible. I find this question difficult to answer because I do not
Know what precise meaning those who have discussed it have been
givmg to the term “incorrigible.” Probably, difierent philosophers
ve given it different meanings. Professor Price, for example, when
ne argues that basic propositions are incorrigible appears to mean
no more than that our re^ons for acceptmg them are found in our
75 justified in saying of a %'isua] sense-datum

*3ecause one sees it so. For the only arguments
^ ~ ^ favor of the view that some first-order propositions

are incorrigible are arguments against the coherence theoA' of truth.is
snould of course agree that basic propositions were incorrigible,
^ unnatural sense. Dr. von Juhos makes the same state-

ment. But what he appears to mean by it is that there can never
be any ground for abandoning a basic proposition: that once it is
acceptea it cannot subsequently be doubted or denied. In a sense

q ently doubted or demed is always a different proposition. What
I accept now is the proposition “this is red”; what I may doubt or
deny m thirty seconds’ time is the proposition “I was seeing some-
red thirty seconds ago.” But in this sense every proposition
which contains a demonstrative is incorrigible, and not only basic
propositions. And if von Juhos wishes to maintain that some special
sacrosanctity attaches to propositions which purport to be records
of our unm ediate expenences, I think that he is wrong. If I find the

18. Vide Truth and Corrigibility.

19. See his articles in Analysis, Vol. H, and Erkenntnis, Vol TV.

Verification and Experience [ 243 ]

sentence "‘I feel happy” written in my diary under the heading
February 3rd I am not obliged to believe that I really did feel happy
on February Srd, merely because the sentence has the same form
as that which I should utter if I felt happy now. I may indeed be-
lieve it on the ground that I am not in the habit of writing down
false statements in my diary. But that is a different matter.

Professor Moore has suggested to me that what some of those
who say that basic propositions are incorrigible may have in mind
is that we cannot be mistaken about them in the way that we can
be mistaken about other empirical propositions. If I say "'I am in
pain” or “this is red” I may be lying, or I may be using words
wrongly; that is, I may be classifying as “pain” or as “red” some-
thing that would not normally be so classified. But I cannot be mis-
taken in any other way. I cannot be mistaken in the way that I can
be mistaken ff I take this red patch to be the cover of a book. If
this is a fact, it is not a fact about human psychology. It is not just
a merciful dispensation of Providence that we are secured from
errors of a certain kind. It is, if anything, a fact about language.-^^
If Moore is right, it does not make sense to say “I doubt whether
this is red” or “I think that I am in pain but I may be mistaken,”
unless it is merely meant that I am doubting whether “pain” or
“red” is the correct w^ord to use. I believe now that Moore is right
on this point. But whether it is a fact from which any important
conclusions follow I do not profess to know.

20. Cf. John Wisdom, “Philosophical Perplexity,” Proc. Arist, Soc., 1936-7, p. 81.

12

What Is the Aim of Ethics?
BY MORITZ SCHLICK
(translated by DAVID RYNIN)

I. Ethics Seeks Nothing but Knowledge

If there ARE ethical questions which have meaning, and are there-
fore capable of being answered, then ethics is a science. For the cor-
rect answers to its questions will constitute a system of true propo-
sitions, and a system of true propositions concerning an obiect is

and nothing else; its only goal is the truth. Ever^• science is, as such
purely theoretical; it seeks to understand: hence the questfons S

to^nd T- *eo^eticaI problems. As philosophers w-e trv

to find their correct solutions, but their practical 'apDlicatioa. if such
IS possible, does not fall within the sphere of ethics, if anvone studies
aese questions m order to apply the results to life and action his
dealing with ethics has, it is true, a practical end; but ethics itself
never has any other goal than the truth.

So long as the philosopher is concerned viih his pur-="lv th'=‘o
S iie has a human interest 'as 4ll

there t object of his invesiiaation. For him

there is no greater danger than to change from a philosonher into
a morahst, from an investigator into a preacher. Deske for the' truth
Siii. I aPProprmte inspiration for the thinker when he phhoso-
S hk thoughts run the danger of being led^ astray

by his feelings. His wishes, hopes, and fears threaten to encroach
upon tliat objectivity which is the necessars^ presupposition of aU

^ person; but one cannot at the same moment serve

Slf.New'^YoS/lttfS^d Prentice-HaU

Uie publishers. Schlick’s book was first publishe^^ °93o'!“'

[ 247 ]

2. The Subject-matter of Ethics

relaS SS oS’

in daily iS “ ™ ns^ them so often

mean by them The e*h?«! exactly what we

is morSy ‘‘v“iuS >’ tS “ “morality,” or what

human cLSt what or “norm” of

by the oldest simplest word" ^ tv to name it

And wdS

s’;“oft\s ™idS“c“*d“ to'/rSo*

else with it. Since ethics is ireSenS 'th-S 2 *™*r°“f “>’l>inS

" i£

STrs,' nor“i afsSj ta uTa f H I-"-"

ro^sf ~s.eT 22

:r~slfHSr" ““-nfLS:

is obviins that no sci-nce caifhf* *' ™ ‘i'iP=™n“' It

"“-SSian?raloS:.a“^^^
P aiX tv»T;re“ 'STead'\“t“-
itShl^^resTmlS’^S*”'”'* ^

i-s dte diins or event as o„eVr4L"2?Jt.*S,tn“:

[ 248 ]

. . MOMTZ SCHLICK

i^es the two problems wiU solve neither.

sl^n^y to?" ^ ^"0^2

is concenied and wLrw2sh^X

What Is the Aim of Ethics? [ 249 ]

tiBguisMiig it from all others in a special way. If this were not so
we would have no opportunity and no motive to call it by a special
, name. Every name which is used in discourse for communication
I must have a meaning capable of being indicated. This is indeed self-
i eiddent, and it would not be doubted of the object of any other
I science — only in ethics has it sometimes been forgotten.

I Let us consider some examples outside the field of ethics. Bi-
I ology, the science of life, finds its sphere limited by a group of
I characteristics (a special kind of motion, regeneration, growth, and
I so forth) which belong to all living things, and stand out so clearly
I for everyday observation that — apart from certain critical in-
I stances — the difference between the animate and inanimate is very
; sharply distinguished, without the use of any scientific analysis. It
is only because of this that the concept of life could have first been
formed, and obtained its special name. If the biologist succeeds,
with progressive knowledge, in establishing new and sharper defini-
tions of life, in order better to bring the events of life under general
laws, this means only more precision in, and perhaps extension of,
the concept, without however altering its original meaning.

Similarly the word “light” had a definite meaning before there
:was a science of light, that is, optics, and this meaning determined
the subject-matter of optics. The distinguishing mark tvas in this
case that immediate experience which we call “iighi-sensation,” that
is, a not-fuither-definable datum of consciousness, known only to
the perceiver, the occurrence of which — again apart from critical
instances — indicates the presence of those e\’ents w'hich constitute
the subject-matter of optics. The fact that optics in its modem devel-
oped form is the science of Roentgen rays and radio-* telegraphic
waves as well (because their laws are identical with the laws of
light) enlarges the meaning of the word “optics** without changing
its basis.

As certainly, then, as the expression “moral good*’ makes good
sense, just as certainly must we be able to discover it in a w'ay
analogous to that by which one discovers the meaning of the word
“life” or “light.” But many philosophers see in this a serious difficulty
of ethics, indeed the difficulty, and they are of the opinion that the
sole task of ethics is the discovery of the definition of “good.”

3. On the Definition of Good

! This view can be interpreted in two ways. In the first place, it
could mean that the task of the philosopher is exhausted in describ-
ing exactly the sense in which the word “good” — or bon or gut

[ 250 ]

MORITZ SCHUCK

ayafeWin its moral signification is actuaUy used,
known merely with making clear the already well-

knoTO mea^g, by a stnct formulation of it in other words^fwere

for example

MoorlShS^^f - definitions is (as G. E.

the hiicinp ^ Ethica has pointed out in a similar connection)

f h'S,' r^'? >“S”>Se. Ought wu reaUy to bS=

science shoulcTbp” word? A veiy peculiar case, that a whole
SrindTn anv merely the definition of a con-

are 'after ah Tnlv ’ mterested in mere definitions? They

S\f stand at the besinninl

be a^t mSl ^ ^ definition it would

inter f philosopher woSd

interest himself only m what comes after it. No, the real problems

of ^ different sort. Even though th» task

of etkcs couM be formulated as that of stating what the c-Sod “reaUv

£u“?rt°al^ “?*■"““" “ - the n,e/dloSl

does uo. s.sive tor\°LLTS« ^of^ii^rR^TfS Si

t^ssi rf r s"

d.y wi.h““h1S1fStSS,S1Jr“"”‘="^

of a cSS teSSSA'h ''" “”“®

terpreted ns not . the concept “good” could be in-

Slhfronnp t K ! ^^te formulation of the content

evef be exaS’v^h J^*^"^ f ^ '^^ts would, how-

sSfSii"?S?i;HS

be dieSed“bSesTS;s'‘'kToM' °' f '

y inese norms. The philosopher would have merely

WMt Is the Aim of Ethics? 251 j

to find a fornnilation of it, and we should have before ns the previ-

ousiy considered case.) However, it would be quite absurd to de-
mand of ethics nothing but the arbitrary establishment of the mean-
ing of a word. That would be no achievement at all. Even the prophet
me creator of a new morality, never forms a new concept of morality^
but presupposes one, and asserts only that other modes of behavior
are subsumed under it than those which people have believed up
to that tune. In logical terms, the prophet holds that the acknowl-
^ged content of the concept has a different range from that supposed.

alone can be the meaning when he declares: “Not that is ‘good’
which yon have held as such, but something else!”

pus we see &e view confirmed that in no way is the formulation
of the con^pt of the moral good to be considered as the final task
of e^cs; It cannot be regarded as anything but a mere preparation.

To be sure, tms preparation is not to be neglected; ethics ought
not to spare itself the task of determining the meaning of its Sn-
cept, even though, as we have said, the meaning of the word “f^ood”
may m one sense be assumed as known.

4* Is THE Good Indefinable?

. dangerous to withdraw from this task under the pre-

te:rt that the word “good” is one of those whose meanincr is simple
and unanalyzable, of which therefore a definition, a statement of £
J^otation. IS impossible. What is demanded here need not be a

S?hnw '' sufficient to indi-
te u state what must

sPictlv Lfi acquainted with its content. It is,

stnctiy speaking, also impossible to define what the word “ore-n”

't.e'^® 5 tdeless fix its meaning unambiguousTy, for
'V® a summer meadow, or by point-

u tree. We mentioned above that a" “iic-ht-

1 noTdefiniS fundamental concept of opfics

^ not definable; however, we know exactly what is meant by it be-

seSinn T conditions under which we have'a light-

sensation. In the same way, in ethics we must be able to give ''the

ffiough Its fundamental concept be indefinable. In thirmanner it

wo5d^hi’°"''^^^ meaning of any word, for othenvise it

would have no meamng at aU. It must even be capable of teincr

pMlosophical analysis cannot be necessary for
IS, for the matter concerns merely a question of fact, namely a

[ 251 ]

^ , MC3K1T2. SCHLICK

<^cnption of those conditions under which the ward /

even^tpm^^'^^ for many philosophers to stick to the realm of facts
the facK^ a™ “ ‘^oty to tiasaribe

"IS'J” ?i.sss“rf ”7^ -<S3

xnis theory is of course wholly hvoothetiral tJw> tv.,, j

theXiaS.^ L^JSrwSe«‘‘f ^

assumption that the moral seif is poorirdevSSed kmSf

” sriff utrs; £l“ SeTsr

Its characmrisfe must L can^ f percepdon.

to certain known facts, withoS My°i£ ^ Sn'Soin^“?f

=SHSHSH#H-

. The Formal Characteristic of the Good

iS^S?'fF-=““at

erally been expressed since tTant- tu ^ S^n-

ouph, m do. ifow, to TtLSS a*iSu”ff dSialrff

someone who dem?3Tidc nic^rr^a ^ ’ ii ^ Qesire there belongs

r£-?H7S~? -

S It, m this case the formal characteristic (to be a command

What Is the Aim of Ethics? [ 253 ]

of God) woEld express the very essence of the good. According to
another, perhaps profounder, interpretation, God desires the good
because it is good. In this case its essence must be given by certain
material characters previously to and independently of those formal
determinations. In traditional philosophical ethics the opinion pre-
vails that the author is, for example, human society (utilitariamsm)
or the active seif (eudaimonism) or even no one (the categorical
imperative). From this last proceeds Kant’s doctrine of the ‘‘abso-
lute ought,” that is, a demand without a demander. One of the worst
errors of ethical thought lies in his belief that the concept of the
moral good is completely exhausted by the statement of its purely
formal property, that it has no content except to be what is de-
manded, “what should be.”

6. MaterialL Characteristics-

In opposition to this, it is clear that the discovery of the formal
characters of the good constitutes only a preliminary step in the
determination of the content of the good, in the statement of material
characteristics. If we know that the good is what is demanded, we
must still ask: What is it then that is actually demanded? In answer
to this question we must turn to the author of the command and
investigate his wUi and desire, for the content of his desire is that
which he wishes to happen. When I recommend an action to some-
one as being “good,” I express the fact that I desire it.

So long as the lawgiver is not known with certainty, we must stick
to the laws as they are generally observed, to the formulations of
moral rules as we find them among men. We must discover which
ways of acting (or dispositions, or whatever be the term used) are
called “good” by different people, at different times, by different
wise men or religious writers. Only in this way do come to know^
the content of this concept. From the content it may then be pos-
sible to infer the lawgiving authority, if it cannot be ascertained
otherwise.

In grouping together the individual cases in which something is
designated as morally good, we must search for the common ele-
ments, the characters in which these examples agree or show simi-
larities. These similar elements are the characters of the concept
“good”; they constitute its content, and within them must lie the
reason why one and the same word, “good,” is used for the several
cases.

To be sure, one will at once come upon cases in which nothing

[ 254 ]

MORITZ SCHLICK

common can be found, in which there seems to be a comolete in
«mpatbd.ty; om apd the same thing-for example, poS^^tSl
be ^nsidered moral m one community, and in Lother a^Le^
such a situation Aere are two possibilities. First, there co^?S
eral irr^ucibly different concepts of “good” (which aeree in
purey (^al properly of being somehow “demanded”)- if this

leaas to it, which actions should therefore be demanrif^rl ^

mmmm

or experimce.)

"K r.her» —

„Ser°t pMos„pS”wouId tod

^ ssrSs .‘tr/d^^Sr

meat frL S orl'^" Lr b« S'ifr" Y

SSSS##SSi

IS quite as important to make out the content L causes of Sei

Wimi Is the Aim of Ethics? [ 255 ]

opinions as in any other more regular cases, if the persons in question
axe importaiit as prophets, moral writers, or morally creative men;
or if their teachings disclose hidden currents or impress their morai
judgments on humanity and the future,

7. Moral Norms and Moral Principles

The common characteristics which a group of “good” acts or
dispositions exhibits can be combined in a rule of the form: A mode
of action must have such and such properties in order to be called
“good” (or “evil”). Such a rule can also be called a “norm.” Let
it be understood at once, however, that such a “norm” is nothing
but a mere expression of fact; it gives us only the conditions under
which an act or disposition or character is actually called “good,”
that is, is given a moral value. The setting up of norms is nothing
but the determination of the concept of the good, which ethics under-
takes to understand.

This determination would proceed by seeldng ever new groups
of acts that are recognized to be good, and showing for each of them
the rule or norm which all of their members satisfy. The different
norms, so obtained, would then be compared, and one w^ould order
them into new classes such that the individual norms of each class
had something in common, and thus would all be subsumed under
a higher, that is, a more general, norm. With this higher norm the
same procedure would be repeated, and so on, until in a perfect
case, one would at last reach a highest, most general rule that in-
cluded all others as special cases, and would be applicable to every
instance of human conduct. This highest norm would be the defini-
tion of “the good” and would express its universal essence; it would
be what the philosopher calls a “moral principle.”

Of course, one cannot know beforehand whether one will actu-
ally arrive at a single moral principle. It might w^ell be that the
highest series of rules to which the described way leads simply show^s
no common character, that one has, therefore, to stop with several
norms as highest rules, because despite ah attempts none higher
can be found to which these could be reduced. There would then
be several mutually independent meanings of the expression “moral
good,” several mutually independent moral principles which only in
their totality would determine the concept of morality, or perhaps
several different concepts of the moral, depending upon the time
and the people. It is significant how little these possibilities have,
in general, been considered by philosophers; almost all have at once

sought a single moral principle Quite the cont schlick

practical moral systems whin! ^ true of the

lish an aU-incIusiw Drincinle ° “°t attempt to estab-

stops at the ten"7mSS:;; “ which

the determ^ation^of^the'co^Dt^f consists in

lisfament of one or n ^^tab-

described procedure would exhaust^S"??^^’ ““P^^tion of the
a pure “normative science”* for ifc stlucs. It would be

of a hierarchy of no^s or’mL tv ^ ^ ‘^^^'^^ery

eral points, the moral Drinciolp? criminated in one or sev-

explained or “justified” bj the hlS^r^l? ? ^ower levels would
thrs act moral?” the “XDlflnafir.n the question, “Why is

under these definite rule?’- and if*?° St'ieo, “Because it falls
the acts falling under Ais ^ “^y ^re all

saying, “Because they all faU under Saf be explained by

wirii the highest norm4 h the 1 t nW

— ts the knowledne of th“ vaL^^n^ * Principles

longer possible in “this way" Th-re ^ Justification, no

sees it as a mere normatSe sde;^ “ who

8. Ethics as a “Normative Science”

can have, and in^w^It phrase “nonnative science”

vaiaata I. “ Srs-“'s“'; “

appears that ethics as a normatiL ^ repeatedly

different from the “factual sciSJes ” T? H "" completely

person judged to be good"?” or “When is a

These questions concern mer°\.^^' to be good?”

does ask, “With w/tar ri?ht is explanation. But it

does not trouble itself with what k J^ n ^

is valuable? What should be Jalued^”'S

tioc is quite different. ’ obviously the ques-

fundamentally false^ For°^°eSi^s°fi™^^’'^^ factual sciences is

so only in the sense jusrex^lS?.^'“f^-^ " Justification it does

way, not absolutely. It “i^tifies”’ f^^^rive-hypothetical

extent that it shows that the iudSient “ Judgment only to the
Aat this norm itself is “right ” or certain norm;

by itself, determine. ’ ®^»ow nor.

Even as a nonnaUveVcieSfHeiS^e^ei'r "

mm

' WhM is ihe Aim of Ethics? [ 257 J

more than explain; it can never set up or establish a norm (which
alone would be equivalent to an absolute justification). It is never
' able to do more than to discover the rules of the judgment, to read
them from the facts before it; the origin of norms always lies out-
side and before science and knowledge. This means that their origin
can only be apprehended by the science, and does not lie within it
In other words: if, or in so far as, the philosopher answers the
question “What is good?’* by an exhibition of norms, this means
only that he teUs us what “good” actually means; he can never tell
us what good must or should mean. The question regarding the
validity of a valuation amounts to asking for a higher acknowledged
norm under which the value falls, and this is a question of facL
The question of the justification of the highest norms or the ultimate
values is senseless, because there is nothing higher to which these
could be referred. Since modem ethics, as we remarked, often speaks
of this absolute justification as the fundamental problem of ethics, it
must be said, unfortunately, that the formulation of the question from
which it proceeds is simply meaningless.

The perversity of such a formulation of the question vill be ex-
hibited by a famous example. John Stuart Mill has often been justly
criticized because he thought himself able to deduce from the fact
that a thing was desired that it was in itself desirable. The double
meaning of the word desirable (“capable of being desired” and “worth
desiring”) misled him. But his critics were also wrong, for they
rested their criticism upon the same false presupposition (expressly
formulated by neither), namely, that the phrase “in itself desirable”
had a definite meaning (by “in itself’ I mean “for its own sake,”
not merely as a means to an end); but in fact they could give it
no meaning. If I say of a thing that it is desirable, and mean that
one must desire it as a means if one desires a certain end, then tvcry-
thing is perfectly clear. If, however, I assert that a thing is desirable
simply in itself, I cannot say what I mean by this statement; it is
not verifiable and is therefore meaningless. A thing can be desirable
only with respect to something else, not in itself. Mill believed him-
self able to deduce what is in itself desirable from what actually is
desired; his opponents held that these had nothing to do with one
another. But ultimately neither side knew what it said, for both
failed to give an absolute meaning to the word “desirable.” The
question whether something is desirable for its own sake is no ques-
tion at all, but mere empty words. On the other hand, the question
of what actually is desired for its own sake is of course quite sensible,
and ethics is actually concerned only with answering this question.

258 J

w^ ^op^ne^ »o^:d“2r.rH^°^ SaiXrs:

an absolute justification of desire. ^ ^ continued to search for
9 . Ethics as Factual Science

values, musTbe SrhJd froTw^ or iigbest

fore, no result of eftfcs cSi sten!? ^ ^re-

cannot declare as evil or false those

of life; its norms cannot demand or m at the foundation

a real opposition to those final nnrmQ ^^-^’raing that is in

such opposition occurs it is a^su^e^ rewgiu^d by life. Where
misunderstood his problem, and has fefed " P^osopher has
miwntmgly become a mor^st tha‘ he l»i ^
role of a knower and would orefer tr ancomiortabie in the

The demands and claims of^a mnraTi^ “ creator of moral values,
subjects for investigation for the creative person are merely

five con,ideraao”®Sd £ MS arl';;'

raeanmg of tbe word^“eoc^^^^a^- °° opposition betwesc Ihe
tie Pioaoiog found W Sihilcstir' a?'

Of course occur, for' lanmia^^e and thn"^^ <^PP^£ra ourerence can
daily life. Often the speaker°c,nH ^ thou^t^ are verj- imperfect in
what he expresses, and often his valSion^^°^' as to

pretation of the facts, and wonld\TlT ^

of the mistake. The philosopher would ’ ^ correction

such errors and faulty expressions and^- discovering

true norms that lie at ‘the root’ of -Cave to recognize

them in opposition to the apparSt ' °^ace

beheves himself to follow. in's^rio

It necessaiy to delve deep into the hum^ P^^^aps, find

-ouid .a au ac^al. a.f Vfuit

ness, and even if elifc^were T'uoSL™''”® “ couscions-

-ons WMC de.^e ,s'r^- -

Whai Is the Aim of Ethics?

I* 259 1

pMosophei^ who hold the questions of ethics to be the most noble

and elevated of quesuons just because they do not refer to Se wm

mon IS but concern the pure ought. “

Of course, after one is in the possession of such a svstem of
norms, of a system of applications of the concents 7noH w f

system. And this holds eveii°if tC stnicttire of the

oies, b« are falseinoSSmd luer?" are not the really valid

arbitrarily established. The last case would unagmed and

interest of a game and would makf ^ ^

Ethics as a nonnatSe sSceTooH “"‘hies.”

order of rules, in which all acts and aSSS’ ^ ^'^^^rchical

possess a definite place with resnect to th^ characters would

course this would be true not onlv of • value. And of

also of all possible oS to- S L LT

must beforeLnd supply a plai for '' k-?

bavior. After beconSg'acqVatotefwftrLT^^^

consider the whole svstem withoiit ™ highest norms, one can

by merely considering S vS^l Th behavior,

his moral philosophy^ it wfs indifferenr whi? that for

will actually existed' Hence efhioc o ^hether or not any moral

would exhibit chScSrisrics ofTn -H
have to do with a system of Sfi ^^uld

apphed to actuahtr^d wodd be

but the rules would have meanin<» oifito^' possess any mterest,
cation, and could be investi<^ated“ in J .“bependently of this appli-
Thus someone might have invented relations to one another,
have considered their application tn tb chess, and might

the game had never beeTSeTex^^^^^ if

nary opponents. " " ’ ™ b's mind, between imagi-

10. Ethics Seeks Causal Explanation

ethic?is"S^? xpkfn Z"mo"T "bat the task of

of thing this “good”% whiS '^bat sort

this subject-matter of ethics is not <dv^ tn found that

object-matter of optics, light thatls bv a ‘be

for Its determination the discover? of ,^w , but that

Of ov

[ 260 ]

MORITZ SCHLICS

^ ^ “normative science,” we see

ft? tSI * ^ ^ toe discovery of

fee meaning of the concept “good.” In this it exhausts itse? SeS

oT.^ “ It of a real explanation of the good. It offers ethics

orfy the object which h to be explained. Therefore we have tom
tolje the view of those philosophers who consider ethics

IndT “®"®^yf^?tomative science. No, only where the theory of nomi
to ie Se f™ ^fPl^^tion begin. The former fails 'com^S^
-I important, excitmg questions of ethics, or, worse ^turm
to aside as foreign in essence to ethics; in truth h S eSS

mintog thTmeaSngs o?ke^^^^^

back to one“anothef umH th?t ^ referred

nrniHr>i<.c. ^ untd the highest are reactied. Thece the moral

te relied °o XScil'i”''’''’'

a special cas™rf shown to be

rsf “ bTsi-iS“?s

bavicr '‘5“ “™'- is moral be-

justified by means of an fii Jbest moral norm would be

be ^errej bac “o1 S£ "roge^f'Se'^'

1="' >be

very reason that it is the Jt '* *e

ther justification a f. 3, be senseless to ask for a fur-

ciples, or values themtostoat^SSiT-^* is not the norms, prin-
of explanation but rather th^ f tf^ i f “ capable

stracted. These facts are the

approbation in bnmar. givmg rules, of valuation, of

the life of the soul “VaS’e°’°Te°“^’d “

som. Value, the good,” are mere abstractions, but

WhM is the Aim of Ethics? [ ]

f atoatioE, approbation^ are actual psychic occurrences, and separate
acts of this sort are quite capable of explanation, that is, can be
reduced to one another.

And here lies the proper task of ethics. Here are the remarkable
facts which excite philosophic wonder, and whose explanation has
always been the final goal of ethical inquiry. That man actually
approves of certain actions, declares certain dispositions to be "‘good,”
appears not at all self-explanatory to the philosopher, but often very
astonishing, and he therefore asks his “Why?” Now, in all of the
natural sciences every explanation can be conceived as a causal
explanation, a truth which we need not prove here; therefore the
“why” has the sense of a question concerning the cause of that psy-
chical process in which man makes a valuation, establishes a moral
claim. (We must make clear that when we speak of the discoveiy^ of
the “cause,” we mean by the term “cause” only a popular abbrevia-
tion for the statement of the complete laws governing the event to be
known.)

In other words, the determination of the contents of the concepts
of good and evil is made by the use of moral principles and a system
of norms, and affords a relative justification of the lower moral rules
by the higher; scientific knowledge of the good, on the other hand,
does not concern norms, but refers to the cause, concerns not the
justification but the explanation of moral judgments. The theory of
norms asks, "'What does actually serve as the standard of conduct?”
Explanatory^ ethics, however, asks '*Why does it serve as the standard
of conduct?”

11. Formulation of the Fundamental Question

It is clear that in essence the first question is a dry, formal matter
that could win little interest from man did it not have such importance
for practice, and if the path to its answer did not offer so many op-
portunities for profound insight into human nature. The second
question, however, leads directly to these profundities. It concerns
the real grounds, the actual causes and motives that drive one to
distinguish between good and evil, and call forth the acts of moral
judgment. Not only judgments, but also conduct, for this follows upon
judgment. The explanation of moral judgment cannot be separated
from the explanation of conduct. To be sure, one should not be-
lieve, without further reason, that everyone arranges his conduct
according to Ms moral judgments. Obviously, that would be a false
assumption. The connection, although indissoluble, is more compli-

r 262 ]

*■ ^ MORITZ SCHLICK

^ted mat a man values, approves, and desires is finally inferred
rom ins actions — better from these than from his assertions, though
toese, too, are Imds of action. What kind of demands one makes
of himself and others can only be known from one’s conduct. A man’s
y^uations must somehow appear among the motives of his acts-
mey cannot, m any case, be discovered anywhere else. He who traces
the causes of conduct far enough must come upon the causes of
all approbation. The question of the causes of conduct is, therefore
more general than that of the grounds of moral judgments; its answer
would give more comprehensive knowledge, and it would be meth-
ooopcally profitable to start with it even if it were not necessary
to l^n with the study of conduct as the only thing observable.

should replace the question raised above.
What mohyes cause us to establish moral nonns?” by the other
question, ‘What are the motives of conduct in general?” (We for-
mulate the question in this general way and do not at once restrict
It to moral actions because, according to what has been said, it might
-possible to deduce valuations and their motives just as well, if not
better, irom immoral or neutral acts.) We are the more warranted in
relating our question at once to conduct, since man interests himself
m valuations only because conduct depends upon them. If moral
approbation were something that remained enclosed in the depths

i i! . ^ ™ ^'^y could not exert

e least mfiuence on the life, happiness and unhappiness of man,

^ one would botner himself with it, and the philosopher would
become acquamted with this unimportant phenomenon only by an

.5 concerning the moral judgments

oescribed as the earliest impulse leading to
the formulation of ethical questions, is above aU wonder at his own
actual moral behavior.

'S, the regularity and

ord-r, of all human actions, with the aim of discovering the motives
of moral actions. And we profit in so doing because we can post-
pone the question regarding the essence of morality, the moral prin-
ciple, until we solve the problem of the natural law governing be-
havior in general. When, however, we come to know about action
m general, it will certainly be much easier to leam what is peculiar

define the content of the concept “good”
TOthout difficulty Perhaps it will turn out that we no longef feel
the necessity of detenninmg a sharp boundary for it (just as, after
me physical explanation of light, the question of how and whether
the concept of hght” is to be distinguished from that of heat radi-
ation or ultra-violet radiation loses afl interest).

[ 263 ]

'■ ' ^ WhM Is the Aim of Ethics?

- - : ' ' ■ 12 . The Method of Ethics Is Psychological

Tinas the cenixai problem of ethics concerns the causal explana-
ir’ tioE of moral behavior; all others in relation to it sink to the level of
preliminary or subordinate questions. The moral problem was most
clearly formulated in this way by Schopenhauer, whose sound sense
of reality led him to the correct path here (if not in the solution)
and guarded him from the Kantian formulation of the problem and
from the post-Kantian philosophy of value.

' The problem which we must put at the center of ethics is a purely
psycholo^cal one. For, without doubt, the discovery of the motives
I or laws of any kind of behavior, and therefore of moral behavior, is
a purely psychological afiair. Only the empirical science of the laws
which describe the life of the soul can solve this problem. One
might wish to derive from this a supposedly profound and destructive
objection to our formulation of the problem. For, one might say,
“In such case there would be no ethics at aU; w^hat is called ethics
would be nothing but a part of psychology!” I answer, "'Why
shouldn’t ethics be a part of psychology?” Perhaps in order that
the philosopher have his science for himself and govern autonomously
in tMs sphere? He w^ould, indeed, thereby be freed of many burden-
some protests of psycholog}^ If he laid down a command, ''Thus
shall man act,” he w^ould not have to pay attention to the psycholo-
^t who said to him, “But man cannot act so, because it contradicts
psychological laws!” I fear greatly that here and there this motive,
though hidden, is at work. However, if one says candidly that “there
is no ethics,” because it is not necessary to label a part of psychology
by a special name, then the question is merely terminological.

It is a poor recommendation of the philosophical spirit of our
age that w^e so often attempt to draw strict lines of division between
the sciences, to separate ever new disciplines, and to prove their
autonomy. The true philosopher goes in the opposite direction; he
does not wish to make the single sciences self-sufficient and inde-
pendent, but, on the contrary, to unify and bring them together; he
wishes to show that what is common to them is what is most essen-
tial, and that what is different is accidental and to be viewed as
belonging to practical methodology. Sub specie aeiernitatis there is
for him only one reality and one science.

Therefore, if we decide that the fundamental question of ethics,
i “Why does man act morally?” can be answered oiffy by psychology,

1 we see in this no degradation of, nor injury to, science, but a happy
simplification of the world-picture. In ethics we do not seek inde-
i pendence, but only the truth.

13

The Emotive Meaning

of Ethical Terms

BY C. L. STEVENSON

I

Ethical questions first arise in the form “Is so and sc good?” or
‘Is this alternative better than that?” These questions are difficult
partly because we don’t quite know what we are seeking. We are
asking, “Is there a needle in that haystack?” without even knowing
just what a needle is. So the first thing to do is to examine the ques-
tions themselves. We must tiy^ to make them clearer, either by de-
fining the terms in w^hich they are expressed, or by any other method
that is available.

The present paper is concerned wholly with this preliminar}^ step
of making ethical questions clear. In order to help answer the ques-
tion ‘Ts X good?” we must subsutute for it a question which is
free from ambiguity and confusion.

It is obvious that in substituting a clearer question we must not
introduce some utterly different land of question. It won’t do (to
take an extreme instance of a prevalent fallacy) to substitute for ‘Ts
X good?” the question “Is X pink with yellow trimmings?” and
then point out how^ easy the question really is. This would beg the
original question, not help answer it. On the other hand, we must not
expect the substituted question to be strictly “identical” with the
original one. The original question may embody hypostatization,
anthropomorphism, vagueness, and all the other ills to which our
ordinary discourse is subject. If our substituted question is to be
clearer, it must remove these ills. The questions wiU be identical only
in the sense that a child is identical with the man he later becomes.
Hence we must not demand that the substitution strike us, on imme-
diate introspection, as making no change in meaning.

This article first appeared in Mind, 1937. It is reprinted with tiie kind perxoission
of Professor Stevenson and the editor of Mind.

[ 264 ]

: Emotive Meaning of Ethical Terms . [ 265 ]

• Just how, then, must the substituted question be related to the
original? Let us assume (inaccurately) that it must result from re-
placing “good” by some set of terms which define it. The question
then resolves itself to this: How must the defined meaning of “good”
■'he related to its original meaning?

I answer that it must be relevant. A defined meaning will be
called “relevant” to the original meaning under these circumstances:
Those who have understood the definition must be able to say all
that they then want to say by using the term in the defined way.
They must never have occasion to use the term in the old, unclear
sense. (If a person did have to go on using the word in the old
sense, then to this extent his meaning would not be clarified, and the
philosophical task w^ould not be completed.) It frequently happens
that a word is used so confusedly and ambiguously that we must
give it several defined meanings, rather than one. In this case only
the whole set of defined meanings will be called “relevant,” and any
one of them will be called “partially relevant.” This is not a rigorous
treatment of relevance, by any means; but it will strvQ for the
present purposes.

Let us now turn to our particular task — that of giving a relevant
definition of “good.” Let us first examine some of the ways in which
others have attempted to do this.

The word “good” has often been denned in terms of approval,
or similar psychological attimdes. We may take as typical examples:
“good” means desired by me (Hobbes); and “good” means ap-
proved by most people (Hume, in effect).* It will be convenient
to refer to definitions of this sort as “interest theories,” following
Mr. R. B. Perry, although neither “interest” nor “theory” is used in
the most usual way.

Are definitions of this sort relevant?

It is idle to deny their partial relevance. The most superficial
inquiry wiH reveal that “good” is exceedingly ambiguous. To main-
tain that “good” is never used in Hobbes’s sense, and never in
Hume’s, is only to manifest an insensitirity to the complexities of
language. We must recognize, perhaps, not only these senses, but
a variety of similar ones, differing both with regard to the kind of
interest in question, and with regard to the people who are said to
have the interest.

* [The author has requested that the following note be added here: For a more
adequate treatment of Hume’s views see my Ethics and Language (Yale University
Press, 1944), Chap. XII, Sect. 5. In the present paper the references to Hume are
to be taken as references to the general family of definitions of which Hume’s is
typical; but Hume’s own definition is somewhat different from any that is here
specifically stared. Perhaps the same should be said of Hobbes.]

[ 266 ]

„ . C. L. STEVENSON

Z ^ Tlie essential question is not whether

GmISd Briefly :

teS^ of SSreT^ ^ relevantly be defined L

SO defined? w relevantly

*1! qSm “l5 y ”j?“°”f = " ““i" it”' *‘>"”'1

thfc ^ good?” SO difficult, they have been graspin-^ for

terms orinterest°Tf"^°°^’”- relevantly defined in

Srani anl. r? °° “^ood” in terns of inter-

3 ^ nswer the question when thus interpreted we mav be

entirely. Of course this oSer sense of “gLd^
TmS Sv" ■' ""i' ** “ “■*-=; bu. .ha.

Now many have maintained that interest theories are inr fmm
being completely relevant. They have arid SfsS SeSe^

neglech the very sense of “good” which is iSost vital And^certainlv
their apments are not without plausibility. certainly,

“vital” sense of “good”? The answers

scarcely detfnJnT’

whether' LmethiS'is “'ojd”"' ■ni."'''' •' lisagres about

de^Mou. For cf„siher".r

cTmS:‘“'r,3re'li?; SS”. *?, HobbL.ViTbt

aesire tins. ihat isn t so, xor / don't” Th^ sd^^Wq
J not contraaicting one another, and think thev are, oniv becaute

“Jood” pronouns. The definition,

cfuld neonw”^ Community, is also excluded, for how

could people from different communities disasree?i

In the second place, “goodness” must have so to sneal-

a?™- ^ recognizes X to be “good” mist )pso

facto acquire a stronger tendency to act in its favor than he other-

Foi accordin^To^HuiT^^t the Humian type of definition,

^imnixr tr. ^ Tccognize that something is “good” is

Tv if I*' ““’'’"‘y “PP"”' ”P ■'• 6'arly: a mrS

may see ri iat Uie majonq- approve of X wittiout haviug, iLself, a

L See G. E. Moore’s Philosophical Studies, pp. 332 - 334 .

Xke Emotive Meaning of Ethical Terms [267]

Stronger tendency to favor it. This requirement excludes any attempt
"to define “good” in terms of the interest of people other than the
speaker.^

In the third place, the “goodness” of anything must not be verifi-
able solely by use of the scientific method. “Ethics must not be
psychology.” This restriction rules out all of the traditional interest
theories, without exception. It is so sweeping a restriction that we
must examine its plausibility. What are the methodological implica-
tions of interest theories which are here rejected?

According to Hobbes’s definition, a person can prove Ms ethical
judgments, with finality, by showing that he is not making an intro-
spective error about Ms desires. According to Hume’s definition, one
may prove ethical judgments (roughly speaking) by taking a vote.
This use of the empirical method, at any rate, seems Mghly remote
from what we usually accept as proof, and refiects on the complete
relevance of the definitions which imply it.

But aren’t there more complicated interest theories which are
immune from such methodological implications? No, for the same
factors appear; they are only put off for a wmle. Consider, for ex-
ample, the definition: “X is good” means most people would approve
of X if they knew its nature and consequences. How, according to
this definition, could prove that a certain X was good? We should
first have to find out, empirically, just what X w^as like, and what
its consequences would be. To tMs extent the empirical method, as
required by the definition, seems beyond inteliigent objection. But
what remains? We should next have to discover w^hether most
people would approve of the sort of thing we had discovered X to
be. TMs couldn’t be determined by popular vote — ^but only because
it would be too difficult to explain to the voters, beforehand, w^hat the
nature and consequences of X really w^ere. Apart from this, voting
would be a pertinent method. We are again reduced to counting
noses, as a perfectly final appeal.

Now we need not scorn voting entirely. A man w^ho rejected
interest theories as irrelevant might readily make the follo\ring state-
ment: “If I believed that X would be approved by the majority,
when they knew all about it, I should be strongly led to say that X
was good.” But he would continue: "'Need I say that X w^as good,
under the circumstances? Wouldn’t my acceptance of the alleged
""final proof result simply from my being democratic? What about
the more aristocratic people? They would simply say that the ap-
proval of most people, even when they knew^ aU about the object

2. See G. C. Field’s Moral Theory, pp. 52, 56-57.

I : C 268 ]

of their approval simnlv t.- ^'^'^^enson

^ything, and they woiJld probX’^df of

low state of people’s iotereL ’’ Jt the

^nsiderations, that the definhion w JS? h these

^p^sed democratic ideals from the stnrf ^-ri? has pre-

theories and others may method, as implied by interest

different way. Mr. G. E ^ “S

question is chiefly pertinent the open

scientifically knowable properties a thfnl*^’ ®^tter what set of
m effect), you will find, on carrful im ° hfoore,

question to ask whether anwhin^ hf “ ts an open

It IS difficult to believe that 'thic ^ properties is good

fused one, or that it seems fpen o Jv hi " totally^cot

good. Rather, we must be usmcr ^ ■'^uuse of the ambiguity of
not definable, relevantly in term^ which is

able_ That is, the scientifc method ? know-

These, then are th^ ° sufficient for ethics s

mteffigent disagreement; (2) fl'inusi jl 7"'® a topic for

-s. ao, ^ u;zzt

II

I^me prLem my'posiS dogmrnfcSy judgments. First

vary irom tradition. aticallj, showing to what extent I

fZVTlZToi ^^ven above, are perfectly
l£ ^^^^rements; and that no traditinl satisfies all

£™ J' S "°‘ topl/lha “Cf.rt”

a Platonic Idea, or of a Cntf> ^ • ^ust be explained in

unique, unanalyxable property On th Imperative, or of an

ments cap be me. by ““ -I*”

prauppostuon xhich all the traditionaUm^' ‘a “P

Traditional interest theories hold rh f rlieor/ei’ have made
scnpuve of the existing s^afo of statements are de-

information about Wesr (mU sL

!!!i7 what the state of ffiS?’- Judgments

The Emotive Meaning of Ethical Terms [ 269 ]

or to indicate what the state of interests would be under specified
circnmstaBces.) It is this emphasis on description, on informatioji^
which leads to their incomplete relevance. Doubtless there is al-
ways some element of description in ethical judgments, but this is
by "no means aH. Their major use is not to indicate facts, but to
create an influence. Instead of merely describing people’s interests,
they change or intensify them. They recommend an interest in an
object, rather than state that the interest already exists.

For instance: When you tell a man that he oughtn’t to steal, your
object isn’t "merely to let him know that people disapprove of
stealing. You are attempting, rather, to get him to disapprove of it.
Your ethical judgment has a quasi-imperative force which, operating
through suggestion, and intensified by your tone of voice, readily
permits you to begin to influence ^ to modify^ his interests. If in the
end you do not succeed in getting him to disapprove of stealing, you
will feel that you’ve failed to convince him that stealing is wrong.
You will continue to feel this, even though he fully acknowledges
that you disapprove of it, and that almost everv^one else does. V/hen
you point out to him the consequences of his actions — consequences
which you suspect he already disapproves of — these reasons w^hich
support your ethical judgment are simply a means of facilitaticg
your infiuence. If you think you can change his inieresis by maldng
vivid to him how' others wiU disapprove of him, you will do so:
otherwise not. So the consideration about other people’s interest is
just an additional means you may employ, in order to move him,
and is not a part of the ethical judgment itself. Your ethical judg-
ment doesn’t merely describe interests to him. it directs his very
interests. The difference between the traditional interest theories
and my view’ is like the difference between describing a desert and
irrigating it.

Another example: A munition maker declares that w’ar is a
good thing. If he merely meant that he approved of it, he would
not have to insist so strongly, nor grow so excited in his argument.
People would be quite easily convinced that he approved of it. If
he merely meant that most people approved of war, or that most
people would approve of it if they knew the consequences, he w^ould
have to yield his point if it were proved that this wasn’t so. But he
wouldn’t do this, nor does consistency require it. He is not describing
the state of people’s approval; he is trying to change it by his influ-
ence. If he found that few people approved of war, he might insist
all the more strongly that it wms good, for there would be more
changing to be done.

rp, - , C. L. STEVENSON

oto.T“ M iXS r- f “ “y

MMicmg pe<2k bS^ "S “* “S^i” I ™ oo^

times goes o? S 4e ^

influence is bad ^that is if the h ^ naunition maker’s

disapproval of the man, ’and^o people’s

actions — ^I should ai- arinths.,- +• u ^ disapprove of his own

taking. But this is not the preS

ter^, but am indicating how they are Sd^^S v“°
in his use of “good ” niustratL mumtion maker,

just as weh as" does

each of us a desire for thf-hc^ * to encourage in

good is peLe " that the sup?em“

interplay and readj ™mem^ of^ complicated

plainly from more gS oL^Z T

arated communities have d T °°f ‘ sep-

extent because IZl otn

Now clearly this influence doesn’t onp t° influences,

alone; words play a great oart PpS ^^ through sticks and stones
courage certaiS ihnSSs'^ a^d bS

others. Those of forceful D-r^nnfr?^ anotner, to discourage

people, for complicated hTstm^f commands which weaker

obey, quite auart from fears rn dificult to. dis-

brought to bear by w-riters and influence is

erted, to an enormous ext^ bvT^^^^^

pbysical force or material rewa^rcT Th^ nothing to do with

influence. Being suited for use in’ facilitate such

which men’s attitudesinay bSTed^^nif ^ bv

that we find a greater then,

munity than in those of different attitudes of one com-

JHdgments propagate themselves

t^ may influence the arrival of ?nn^ S°°d”;

the same ethical judgment whirh ^ person, who then makes
son, and so on. In C L L Per-

r"r-“ ~

ow does an ethical sentence acquire its

The Emotive Meaning of Ethical Terms [ 271 ]

l^wer of mflnencmg people — why is it suited to suggestion? Again,
what has this influence to do with the meaning of ethical terms?
And finally, do these considerations really lead ns to a sense of
“good” which meets the requirements mentioned in the preceding
■ section?

Let ns deal first with the question about meaning. This is far
from an easy question, so we must enter into a preliminary inquiry
about meaning in general. Althou^ a seeming digression, this will
prove indispensable.

m

Broadly speaking, there are two different purposes which lead
us to use language. On the one hand we use words (as in science)
to record, clarify, and communicate beliefs. On the other hand we
use words to give vent to our feelings (interjections), or to create
moods (poetry), or to incite people to actions or attitudes (oratory).

The first use of words I shall call “descriptive”; the second,
“dynamic.” Note that the distinction depends solely upon the pur-
pose of the speaker.

When a person says “Hydrogen is the lightest known gas,” his
purpose may be simply to lead the hearer to believe this, or to be-
lieve that the speaker believes it. In that case the words are used
descriptively. W^en a person cuts himself and says “Damn,” his
purpose is not ordinarily to record, clarify, or communicate any
belief. The word ig used dynamically. The two ways of using words,
however, are by no means mutuaiiy exclusive. This is obvious from
the fact that our purposes are often complex. Thus when one says
‘T want you to close the door,” part of his purpose, ordinarily, is
to lead the hearer to believe that he has this want. To that extent
the words are used descriptively. But the major part of one’s purpose
is to lead the hearer to satisfy the want. To that extent the w^ords
are used d3mamicaiiy.

It very frequently happens that the same sentence may have a
dynamic use on one occasion, and may not have a dynamic use on
another; and that it may have different dynamic uses on different
occasions. For instance: A man says to a visiting neighbor, “I am
loaded down with work.” His purpose may be to let the neighbor
know how life is going with him. This would not be a dynamic
use^ of words. He may make the remark, however, in order to drop
a hint. This would be dynamic usage (as well as descriptive). Again,
he may make the remark to arouse the neighbor’s sympathy. This
would be a different dynamic usage from that of hinting.

C, L. STEVBNSON

Or agaiii, when we say to a man, “Of course you won’t make
those mistakes any more,” we may simply be making a prediction.
But we are more likely to be using “suggestion,” in order to en-
courage Mm and hence keep Mm from making mistakes. The first
use would be descriptive; the second, mainly dynamic.

From these examples it will be clear that we can’t determine
whether words are used dynamically or not, merely by reading the
dictionary — even assuming that everyone is faithful to dictionary
meanings. Indeed, to know whether a person is using a word
dynamically, we must note Ms tone of voice, Ms gestures, the gen-
eral circumstances under which he is speaking, and so on.

We must now proceed to an important question: What has the
dynamic use of words to do with their meaning? One thing is clear
— ^we must not define “meaning” in a way that would make meaning
vary with dynamic usage. If we did, we should have no use for the
term. All that we could say about such “meaning” would be that it
is very complicated, and subject to constant change. So we must
certainly distinguish between the dynamic use of words and their
meaning.

It doesn’t follow, however, that we must define “meaning” in
some non-psychological fashion. We must simply restrict the psy-
chological field. Instead of identifying meaning with all the psycho-
logical causes and effects that attend a word’s utterance, we must
identify it with those that it has a tendency (causal property, dis-
positional property) to be connected with. The tend^enc}’^ must be of
a particular kind, moreover. It must exist for all who speak the
language; it must be persistent; and must be realizable more or less
independently of determinate circumstances attending the word’s
utterance- There will be further restrictions dealing with the inter-
relation of words in different contexts. Moreover, we must include,
under the psychological responses which the words tend to produce,
not only immediately introspectabie experiences, but dispositions to
react in a given way with appropriate stimuli. I hope to go into these
matters in a subsequent paper. Suffice it now to say that I think
“meaning” may be thus defined in a way to include “propositional”
meaning as an important kind. Now a word may tend to have causal
relations which in fact it sometimes doesn’t; and it may sometimes
have causal relations which it doesn't tend to have. And since the
tendency of words which constitutes their meaning must be of a
particular kind, and may include, as responses, dispositions to reac-
tions, of which any of several immediate experiences may be a sign,
then there is nothing surprising in the fact that words have a per-

/The Emotive Meaning of Ethical Terms [ 273 ]

-laaiieBt meaning, in spite of the fact that the immediately intro-
spectable experiences which attend their usage are so highly varied.

When “meaning” is defined in this way, meaning will not include
dynamic use. For although words are sometimes accompanied by
dynamic purposes, they do not tend to be accompanied by them in
the way above mentioned. E.g., there is no tendency realizable inde-
pendently of the determinate circumstances under which the words
are uttered.

There will be a kind of meaning, however, in the sense above
defined, which has an intimate relation to dynamic usage. I refer
to “emotive” meaning (in a sense roughly like that employed by
Ogden and Richards).^ The emotive meaning of a word is a tendency
of a word, arising through the history of its usage, to produce
(result from) affective responses in people. It is the immediate
aura of feeling which hovers about a word. Such tendencies to pro-
duce affective responses cling to words vory tenaciously. It would
be difficult, for instance, to express merriment by using the inter-
jection “alas.” Because of the persistence of such afiective tenden-
cies (among other reasons) it becomes feasible to classify them as
“meanings.”

Just what is the relation between emotive meaning and the
dynamic nse of words? Let us take an example. Suppose that a
man is talking with a group of people which includes Miss Jones,
aged 59. He refers to her, without thinking, as an “old maid.” Now
even if his purposes are perfectly innocent — even if he is using the
words purely descriptively — Miss Jones won’t think so. She will
think he is encouraging the others to have contempt for her, and
wiU draw in her skirts, defensively. Tne man might have dons better
if instead of saying “old maid” he had said “elderly spinster.” The
latter words could have been put to the same descriptive use, and
would not so readily have caused suspicions about the dynamic use.

“Old maid” and “elderly spinster” differ, to be sure, only in
emotive meaning. From the example it will be clear that certain
words, because of their emotive meaning, are suited to a certain
kind of dynamic use — so well suited, in fact, that the hearer is likely
to be misled when we use them in any other way. The more pro-
nounced a word’s emotive meaning is, the less likely people are to
use it purely descriptively. Some words are suited to encourage
people, some to discourage them, some to quiet them, and so on.

4. Sec The Meaning of Meaning, by C. K. Ogden and I. A, Ricimrda. Offl p.
125, second edition, there is a passage on ethics which was the source of the
ideas embodied in this paper.

[ 274 ]

. C. L. STEVENSON

to dynamic purposes are not

piuSriut fhli “ persistently than do the dynamic

5.H / “ contingent relation between emo-

W^nrvx -f ^ dynamic purpose: the former assists the latter
th?. 7® terms in a way tharneieS

SliSfc°S S!T^’ we are likely to be confusing. L /eod pfople
thJy te dynamically less often tLn

(•‘W=- incW« tt?hetro”‘h“ei“ ^■

s!tpM tofind If used, we should

see. to cast d^uht

that - ‘W™*!"??,' '’“T"’ ““ •" “ assuming

take the place of “This is crnnrf’^ ^

not purelv descriotivelv Juft ^ former sentence must be used

be used to promL a very « must

question, a veiw easily resisted! kiifrf'^ non-moral sense in

that “we” refers to th- ^ ^ 'Po the extent

tial to suggestion o?Ie2S\e

rather than merely to believe it AnH f 2 ^

to the speaker thl sentenr^ i t k °

of indicatin^bSef ?£°f 7“^^ descriptive use

inteijecto^'dSaSc fank-?' Q^usi-

interest. (This immediate exnreQs° direct expression to the

of sugsestion It is difficuit^tn Poolings assists in the process

enthuS'asm.) disapprove in the face of another’s

For an example of a case where “We like this” is used in the

■ The Emotive Mecming of Ethical Terms [ 275 ]

dynamic way that “This is good” is used, consider the case of a
^ mother who says to her several children, “One thing is certain, we
Ml like to be neat/' If she really believed this, she wouldn’t bother
to say so. But she is not using the words descriptively. She is en-
couraging the children to like neatness. By telling them that they
like neatness, she will lead them to make her statement true, so to
speak. If, instead of saying “We all like to be neat” in this way,
she had said “It’s a good thing to be neat,” the effect would have
been approximately the same.

But these remarks are stiH misleading. Even when “We like it”
is used for suggestion, it isn’t quite like “This is good.” The latter
is more subtle. With such a sentence as “This is a good book,” for
example, it would be practically impossible to use instead “We
like this book.” When the latter is used, it must be accompanied
by so exaggerated an intonation, to prevent its becoming confused
with a descriptive statement, that the force of suggestion becomes
stronger, and ludicrously more overt, than when “good” is used.

The definition is inadequate, further, in that the definiens has
been restricted to dynamic usage. Having said that dynamic usage
was different from meaning, I should not have to mention it in giv-
ing the meaning of “good.”

It is in connection with this last point that we must return to
emotive meaning. The word “good” has a pleasing emotive meaning
which fits it especially for the dynamic use of suggesting favorable
interest. But the sentence “We like it” has no such emotive mean-
ing. Hence my definition has neglected emotive meaning entirely.
Now to neglect emotive meaning is likely to lead to endless con-
fusions, as we shall presently see; so I have sought to make up for
the inadequacy of the definition by letting the restriction about dy-
namic usage take the place of emotive meaning. What I should do,
of course, is to find a definiens whose emotive meaning, like that of
“good,” simply does lead to dynamic usage.

Why didn’t I do this? I answer that it isn’t possible, if the
definition is to afford us increased clarity. No two words, in the first
place, have quite the same emotive meaning. The most we can
hope for is a rough approximation. But if we seek for such an ap-
proximation for “good,” we shall find nothing more than synonyms,
such as “desirable” or “valuable”; and these are profitless because
they do not clear up the connection between “good” and favorable
interest. If we reject such synonyms, in favor of non-ethical terms,
we shall be highly misleading. For instance: “This is good” has
something like the meaning of “I do like this; do so as well.” But

f 276 ]

J c. L. STEVENSON

this is certainly not accurate. For the imperative makes an appeal
to the consdous efforts of the hearer. Of course he can’t Uke some-
tog just by tiymg. He must be led to like it through suggestion.
Hence an ethical sentence differs from an imperative in that it en-
ables one to make changes in a much more subtle, less fully con-
scious way. Note that the ethical sentence centers the hearer’s
attention not on his interests, but on the object of interest, and
thereby facilitates suggestion. Because of its subtlety, moreover, an
ethical sentence readily permits counter-suggestion, and leads to the

^e and take situation which is so characteristic of arguments
about values.

Strictly sf^aking, then, it is impossible to deffne “good” in terms
of favorable interest if emotive meaning is not to be distorted. Yet
It IS possiole to say that “This is good” is about the favorable interest
of tne speaker and the hearer or hearers, and that it has a pleas-
meaning which fits the words for use in suggestion.
Tms is^a rough description of meanine. not a definition. "But it
seiwes the same clarifying function that a definition ordinarily does:
and that, after all, is enough.

added about the moral use of “aood.” This
differs from the above in that it is about a different kind" of interest,
nstead of being about what the hearer and sneaker lik^, it is about
a stronger sort of approval. When a person likes something, he is
pleased wnen it prospers, and disappointed when it doesn’t When
a person morally approves of something, he experiences a rich feel-
mg or_ security when it prospers, and is indignant, or “shocked”
w en It doesn’t.^ These are rough and inaccurate examples of the
many factors ivhich one would have to mention in distineuishina
tne two^itmds^or interest. In the moral usage, as well as in the non-
morm, good” has an emotive meaning which adapts it to suggestion.

And now, are these considerations of anv * importance? Why
do I stress emotive meanings in this fashion? Does the omission of
them really lead people into errors? I think, indeed, that the errors
resulting from such omissions are enormous. In order to see this
however, we must return to the restrictions, mentioned in section I,’
with which the ‘vital” sense of “good” has been expected to comply.

The first restriction, it will be remembered, had to do with dis-
agreement. Now there is clearly some sense in which people disagree
on ethical points; but we must not rashly assume that all disagree-

'The Emotive Meaning of Ethical Terms [ 277 ]

meiit is modelled after the sort that occurs in the natural sciences.
We must distinguish between “disagreement in belief’ (typical of
the' sciences) and “disagreement in interest.” Disagreement in belief
occurs when A believes p and B disbelieves it. Disagreement in
interest occurs when A has a. favorable interest in X, when B has
an unfavorable one in it, and when neither is content to let the
other’s interest remain unchanged.

Let me give an example of disagreement in interest. A. “Let’s
go to a cinema to-night.” B. “I don’t want to do that. Let’s go to
the symphony.” A continues to insist on the cinema, B on the sym-
phony. This is disagreement in a perfectly conventional sense, lliey
can’t agree on where they want to go, and each is trying to redirect
the others interest. (Note that imperatives are used in the example.)

It is disagreement in interest which takes places in ethics. When
C says “This is good,” and D says “No, it’s bad,” we have a case of
suggestion and counter-suggestion. Each man is trying to redirect
the other’s interest. There obviously need be no domineering, since
each may be willing to give ear to the other’s influence; but each
is trying to move the other nonetheless. It is in this sense that
they disagree. Those who argue that certain interest theories make
no provision for disagreement have been misled, I believe, simply
because the traditional theories, in lea\ing out emotive meaning,
give the impression that ethical judgments are used descriptively
only; and of course when judgments are used purely descriptively,
the only disagreement that can arise is disagreement in belief. Such
disagreement may be disagreement in belief about interests; but
this is not the same as disagreement in interest. My definition doesn’t
provide for disagreement in belief about interests, any more than,
does Hobbes’s; but that is no matter, for there is no reason to be-
lieve, at least on common-sense grounds, that this kind of disagree-
ment exists. There is only disagreement in interest. (We shall see
in a moment that disagreement in interest does not remove ethics
from sober argument — that this land of disagreement may often be
resolved through empirical means.)

The second restriction, about “magnetism,” or the connection
between goodness and actions, requires only a word. This rules out
only those interest theories which do not include the interest of the
speaker, in defining “good,” My account does include the speaker’s
interest; hence is immune.

The third restriction, about the empirical method, may be met
in a way that springs naturally from the above account of disagree-
ment. Let us put the question in this way: When two people dis-

C. L. STEVENSON

agree over an ethical matter, can they completely resolve the dis-
agreement through empirical considerations, assuming that each
applies the empirical method exhaustively, consistently, and with-
out error?

I answer that sometimes they can, and sometimes they cannot;
and that at any rate, even when they can, the relation between
empirical knowledge and ethical judgments is quite different from
the one which traditional interest theories seem to imply.

This can best be seen from an analogy. Let’s return to the ex-
ample where A and B couldn’t agree on a cinema or a symphony.
The example differed from an ethical argument in that imperatives
were used, rather than ethical judgments; but was analogous to
the extent that each person was endeavoring to modif}? the other’s
interest. Now^ how would these people argue the case, assuming that
they were too intelligent just to shout at one another?

Qearly, they would give “reasons” to support their imperatives.-
A might say, “But you know*, Garbo is at the Bijou.” His hope is
that B, who admires Garbo, will acquire a desire to go to the cinema
when he knows what play will be there. B may counter, ‘"But Tos-
canini is guest conductor tonight, in an all-Beethoven program.”
And so on. Each supports his imperative C‘Lefs do so and so”)
by reasons which may be empirically established.

To generalize from this: disagreement in interest mav be rooted
in disagreement in belief. That is to say, people who disagree in
interest would often cease to do so if they knew the precise nature
and consequences of the object of their interest. To this extent
disagreement in interest may be resolved by securing agreement m
belief, which in turn may be secured empirically.

This generalization holds for ethics. If A and B. instead of using
imperatives, had said, respectively, “It would be beirer lo go to the
cinema,” and “It would be better to go to the svmphonv,” the reasons
which they would advance would be roughly the same. They would
each give a more thorough account of the object of interest, with the
purpose of completing the redirection of interest wffich w^as began
by the suggestive force of the ethical sentence. On the whole, of
course, the suggestive force of the ethical statement merely exerts
enough pressure to start such trains of reasons, since the reasons are
much more essential in resolving disagreement in interest than the
persuasive effect of the ethical judgment itself.

Thus the empirical method is relevant to ethics simply because
our knowledge of the world is a determining factor to our interests.
But note that empirical facts are not inductive grounds from w^hich

Jke Emotive Meaning of Ethical Terms [ 279 ]

* iJie etMcal jiidgment problematically follows. (This is what traditional
interest theories imply.) If someone said ‘‘Qose the door,” and added
the reason ‘"We’ll catch cold,” the latter would scarcely be called
an inductive ground of the former. Now imperatives are related to

• the reasons which support them in the same way that ethical judg-
"ments are related to reasons.

Is the empirical method sufficient for attaining ethical agree-
\iiient? Qearly not. For empmcal knowledge resolves disagreement
in interest only to the extent that such disagreement is rooted in
disagreement in belief. Not all disagreement in interest is of this sort.
For Instance: A is of a sympathetic nature, and B isn’t. They are
arguing about whether a public dole would be good. Suppose that they
discovered all the consequences of the dole. Isn’t it possible, even
so, that A will say that it’s good, and B that it’s bad? The disagree-
ment in interest may arise not from limited factual knowledge, but
simply from A’s sympathy and B’s coldness. Or again, suppose, in
the above argument, that A was poor and unemployed, and that
B was rich. Here again the disagreement might not be due to different
factual knowledge. It would be due to the different social positions
of the men, together with their predominant self-interest.

When ethical disagreement is not rooted in disagreement in belief,
is there any method by which it may be settled? If one means by
“method” a rational method, then there is no method. But in any
case there is a “way.” Let’s consider the above example, again,
where disagreement was due to A’s sympathy and B’s coldness.
Must they end by saying, “Well, it’s just a matter of our having
different temperaments”? Not necessarUy. A, for instance, may try
to change the temperament of his opponent. He may pour out his
enthusiasms in such a moving way — present the sufferings of the
poor with such appeal — ^that he will lead his opponent to see life
through different eyes. He may build up, by the contagion of his
feelings, an inffuence which will modif}^ B’s temperament, and
create in him a sympathy for the poor which didn’t previously exist.
This is often the only way to obtain ethical agreement, if there is
any way at aU. It is persuasive, not empirical or rational; but that
is no reason for neglecting it. There is no reason to scorn it, either,
for it is only by such means that our personalities are able to grow,
through our contact with others.

The point I wish to stress, however, is simply that the empirical
method is instrumental to ethical agreement only to the extent that
disagreement in interest is rooted in disagreement in belief. There
is Httle reason to believe that ail disagreement is of this sort. Hence

And now, have I really pointed out the ^‘vital” sense of “good’’?
suppose that many will still say “No,” ciaimins that I have
simply failed to set down enough requirements which this sense must
meet, ana that my analysis, like all others given in terms of interest,
is a way of begging the issue. They will say: “When we ask Is X
good? we don’t want mere influence, mere advice. W^e decid-
edly don’t want to be influenced through persuasion, nor are
we fully content when the influence is supported by a wide scientific
knowledge of X. The answer to our question will, of course, modify
our interests. But this is only because an unique sort of iruth will be
revealed to us — a truth v/hich must be apprehended a priori. We
want our interests to be guided by this truth, and nothing else,
io substitute for such a truth mere emotive meaninc and suasesiion
is to conceal from us the very object of our search.’*

I can only answer that I do not understand. What is this truth
to be about? For I recollect no Platonic Idea, nor do I know what to
try to recollect. I find no indefinable property, nor do I know’ w^hat
to look for. And the “self-evident” deliverances of reason, which so
many philosophers have claimed, seem, on examination, to be de-
liverances of their respective reasons only (if of anvone’s) and not
of mine.

I strongly suspect, indeed, that any sense of “good” which is

t I C. L. STEVENSON

&e empirical method is not sufficient for ethics. In any case, ethics
is not psychologjq since psychology doesn’t endeavor to direct our
mterests;^ it discovers facts about the ways in which interests are or
can be directed, but that’s quite another matter.

To summarize this section: my analysis of ethical judgments
meets the three requirements for the “vital” sense of “good” that
were mentioned in section 1. The traditional interest theories fail to
meet these requirements simply because they neglect emotive mean-
ing. This neglect leads them to neglect dynamic usage, and the sort
of disagreement that results from such usage, together with the
method of resohnng the disagreement. I may add that my analysis
amwers Moore’s objection about the open question. Wliatever
scientifically knowable properties a thing may have, it is alw’ays
open to question whether a thing having these (enumerated) qualities
is good. For to ask whether it is good is to ask for influence. And
whatever I may know about an object, I can still ask, quire pertinently,
to be influenced with regard to my interest in it. '

Tlie Emotive Meaning of Ethical Terms [

' expected both to unite itself in synthetic a priori fashion with other
■ concepts, and to influence interests as well, is really a great confusion.
I extract from this meaning the power of influence alone, which I
find the only intelligibie part. If the rest is confusion, however, then
it certainly deserves more than the shrug of one’s shoulders. What
I should like to do is to account for the confusion — ^to examine the
psychological needs which have given rise to it, and to show how
these needs may be satisfied in another way. This is the problem, if
confusion is to be stopped at its source. But it is an enormous prob-
lem, and my reflections on it, which are at present worked out only
roughly, must be reserved until some later time.

I may add that if ‘‘X is good” is essentially a vehicle for sugges-
tion, it is scarcely a statement which philosophers, any more than
many other men, are called upon to make. To the extent that ethics
predicates the ethical terms of anything, rather than explains their
meaning, it ceases to be a reflective study. Ethical statements are
social instruments. They are used in a co-operative enterprise in
which we are mutually adjusting ourselves to the interests of others.
Philosophers have a part in this, as do all men, but not the major part.

Sociology and Physicalism

(translated

BY OTTO NEURATH

BY MORTON MAGNUS AND RALPH RAICO)

I. Physicalism: A Non-metaphysical Standpoint

WittgensKto and

World-Outlook (Wei?^ffaJ ^ Dissemination of the Scientific
will be fr^ToJ^JS^iZTfJ
in all fields by meS? S W.,

to speak of a i misleadiaa

temTwhich does ^

world-outlook (Weltauffassuncrl tc science, and smce

(Weltanschauun<^l coniused with world-view

meat that ‘^Sont^

sciencp QOwS not exist as a discipline, alon<^side

viruT 1 f ™ meaningful statements

thafr chSer " f ^'P » ”»«■

emphasized. Unified science is thf. ”°t “always been sufficiently
collective labor-^ th- ^L I of comprehensive

heolosy biolo^w or pv^n ti, structure of chemistn.-,

TT -i: ^'^en mathematics and io«ic

dM„'?'4““rh.va‘h’” •»« in-

witfaout a school” will have^no mo^^^ hitherto. Thus, the “thinker

P»po^nhovaao„ Must be » foSSt? rri“be egpIS'

me KrirtS2'(tSSi% •PKwta la Vol-
™. of Mr., Mrt.'N.w.i L ;SorC«'cS,;“ ■*'

^'Sodology and Fhysicdism [ 283 ]

to gain iiaiversal acceptance. Only through the cooperative effort of
many thinkers do all its implications become clear. If it is false or
meaningless, i.e., metaphysical, then, of course, it falls outside the
range of uihfied science. Unified science, alongside of which there
exists no ‘‘philosophy” or “metaphysics,” is not the achievement of
isolated individuals, but of a generation.

Some representatives, of the “Vienna Circle” who, like all their
colleagues in this group, explicitly declare that there are no peculiarly
“philosophic truths,” nevertheless still occasionally employ the word
“philosophy.” By this they mean to designate “philosophizing,” the
“operation whereby concepts are clarified.” This concession to
traditional linguistic usage, though understandable for a number of
reasons, easily gives rise to misconceptions. In the present exposition
the term is not employed. We are not here seeking to oppose a new
“Weltanschauung” to an old one, or to improve on an old one by
the clarification of concepts. The opposition, rather, is between ail
world-views and science w^hich is “free of any world-view,” In the
opinion of the “Vienna Circle,” the traditional edifice of metaphysics
and other constructions of a similar nature, consist, insofar as they
do not “accidentally” contain scientific statements, of meaningless
sentences. But the objection to the expression, “philosophizing,” is
not merely a terminological one; the “clarification of the meaning of
concepts” cannot be separated from the “scientific method,” to
which it belongs. The two are inextricably intertwined.

The contributions to unified science are closely interrelated,
whether it be a question of thinking out the implications of new
astronomical observation-statements, or of inquiring into the chemical
laws which are applicable to certain digestive processes, or of re-
examining the concepts of various branches of science in order to
find out the degree to which they are already capable of being con-
nected with one another, in tlie way that unified science demands.
That is to say, every law in unified science must be capable of being
connected, under given conditions, with every other law, in order
to reach new formulations.

It is, of course, possible to delimit different kinds of laws from
one another, as for instance, chemical, biological or sociologicaL
But one may not assert that the prediction of a concrete individual
event depends solely on laws of one of these kinds. Whether, for
example, the burning down of a forest at a certain spot on the earth
will proceed in a certain way depends just as much on the weather
as on whether or not human beings will undertake certain measures.
These measures, however, can only be predicted if the laws of human

r 284 1

; OTTO NEURATH

behavior axe known. That is to say, all types of laws must, under
Siven conditions, be capable of being connected with one another
^ laws, whether chemical, climatological or sociological, must,
therefore, be conceived of as constituents of a system, viz., of unified
science.

construction of unified science a unified language
_( Einheitsprache")\ with its unified syntax, is required. To the
imperfections of syntax in the period preparatory to unified science
one may trace the respective positions of particular schools and ages.

Wittgenstem and other proponents of the scientific world-outlook
who deserve great credit for their rejection of metaphysics, i.e. for
the eh^ation of meaningless statements, are of the opinion that
every individual, m order to arrive at scientific knowledge, has
meaningless word-sequences for “elucidation”
(Wiitgenstsm, j ractatus 6. 54): “My propositions are elucidato.n'
m this way: he who understands me finally recognizes them as
-nseles^^when he has climbed out through them, on them, over
speak, throw away the ladder after he has
^hmbed up on it.) This sentence seems to suggest that one must
as It were undergo repeated purgations of meaningless, i.e., meta-
physic^ statements, that one must repeatedly make use of and then
Jscard^tnis ladder. Only with the help of elucidations, consisting
vha^ are later recog^ed to be mere meaningless sequences of
woras, IS one aple to arrive at the unified language of science. ITiese
e ucidations, which may, indeed, be pronounced metaphysical, do
not, however, appear in isolation in Wittgenstein’s writings: we find
there further expressions which resemble less the rungs df a ladder
parts or an unobtrusively formulated subsidiary metaphysical
doctnne. The conclusion of the Traciatus, “Whereof one cannot
speak, tnereof one must be silent,” is, at least grammaticallv, mis-
Lading. It sounds as if there were a “something” of which one could
not sf^ak. We should rather say: if one really wishes to avoid the
metaphysical attitude entirely, then one will “be silent " but not
about something.”

We have no need of any metaphysical ladder of elucidation. We

matter, although his great signifi-
cance for logic is not, for that reason, to be less highly valued. We
owe him among other things, the distinction between "“tautologies”
md statements about empirical events.” Logic and mathematics
show us w hat linguistic transformations are possible rviihout any

Sociology and Fhysicdism [ 285 ]

extension of meaning, independently of the way in wMch we choose
to fonniilate the facts.

Logic and mathematics do not require any observation state-
ments to complete their structures. Logical and mathematical errors
can be eliminated without recourse to any outside field. This is not
contradicted by the fact that empirical statements may be the occasion
for such corrections. Let us suppose that a captain sails his ship on
to a reef. AU the rules of calculation have been correctly applied, and
the reef is to be found on the maps. In this way an error in the
logarithm tables, which was responsible for the misfortune, could be
discovered, but it also could be discovered independently of such
an experience.

In his “elucidations,” which may also be characterized as “mytho-
logical introductor}^ remarks,” Wittgenstein seems to be attempting
to investigate, as it were, a pre-linguistic state from the point of view
of a pre-linguistic stage of development. These attempts must not
only be rejected as meaningless; they are also not required as a
preliminary step towards unified science. One part of language can,
to be sure, be used to discuss other parts; but one cannot make
pronouncements concerning language as a whole from a “not yet
liaguistic” standpoint, as Wittgenstein and certain representatives of
the “Vienna Circle” seek to do. A part of these endeavors, although
in a modified form, may be suitably incorporated into scientific
work. The rest would have to be discarded.

Nor may language as a whole be set against “experience as a
whole,” “the world,” or “the given.” Thus, every’ statement of the
kind, “The vtiy possibility of science depends on the fact of order
in the universe,” is meaningless. Such statements cannot be salvaged
by counting them as “elucidations,” to which a somewhat less rigorous
criterion applies. There is little difference between such an attempt
and metaphysics in the conventional sense. The possibility of science
is demonstrated by the existence of science. We e.xtend its domain by
augmenting the body of scientific propositions, by comparing new
propositions with the legacy of past scientists, and thus creating a
self-consistent system of unified science capable of being utilized for
successful prediction, Wt cannot as deponents stand aside, as it were,
from our depositions and serve simultaneously as plaintiff, defendant
and judge.

That science keeps within the domain of propositions, that
propositions are its starting point and terminus, is often conceded
even by metaphysicians, of course with the rider that besides science
there exists yet another domain, containing statements which are

( 286 ]

?o“S”^ 1^“% -£ — s

Unified science formulates statements corrects ,

predictions. But it cannot flnt5r-;r,ot» v ’ and makes

even as a fiStS concS W^ ^ t^g

ing today with the spacJ-'tiTe svstem wSrthtf
responds, and thus achieve sucrp^^J ^ ^ ptiysics cor-

statements is that of unified science system of

may be designated phvsicalistr « If ’thi^ t

iished, then it would i ldvIShle i should become estab-

one has in mind sStiStTrn “physicahstic” when

of contempS^ai^- ^IS^To^rfl framed in the spirit

“physical” would then be reserved ^description. The term

narrower sense,” e « for those nf k Pirysical statement in the
Ignoring aU meanfo^ss stilnt «=■

given historical S proTeSs W Proper to a

blending them into a <iQF^nnc’ Proposition to proposition,

for sucSess,.“

II. The Unified Language of Physicalism

vrithoS®e1«5oTrf

not statements, but mer-li °°5 another. Laws are

statements to prediction. (Schiick? from observation

common to the Snd^2?Se^eS'^?de™f language,

"intersensual” and “intersubiective Clearing. It is

asserts today with what he'^ ^ a ^^nccts what the soliloquizer
makes when hL elrs ^ cW? statements he

thorn. Tie oSy S“ss SS “P™

present even in a Uforse cSe P something

sensual" lanie teLs 1 '"f subjective" or “intert

tween," etc.nhat1s ™ n \°° <“”™ < 0 ." “be-

— ' - ’ “• PP "‘“sh E eipressed in the symbol

3 O 'o«r5 ^irklichkeit, 1931.

J. Cf. Otto Neurath, Empirische Soziologie. p. 2.

:'r''-SodaI^>gy md Pkysicdism [ 287 ]

"'scqiieaces of logic and mathematics. It is in this langisage that all
'■‘■predictions are formulated.

The unified language of unified science, which is derivable by
" ''."'and large from modifications of the language of eyeryday life, is
the language of physics. In this connection, it is a matter of indiffer-
ence for the uniformity of the language of physicalism what particular
language the physics of a given period may use. It is of no significance
whether it explicitly employs a four-dimensional continuum in its
more hi^y refined formulations, whether it recognizes a spatio-
temporal order of such a t}^ that the locus of every event is pre-
cisely determined, or whether couplings of placer and velocity-
dispersions, whose precision is limited in principle, figure as basic
elements. It is essential only that the concepts of unified science,
both where they are thought out in the most subtle detail and where
the description remains imprecise, be made to share the current fate
of fundamental physical concepts. It is precisely in this that the point
of view of physicalism is expressed. But all predictions, in whose
confirmation or rejection we see the measure of science, are reducible
to observation-statements, to statements mvolving percipient in-
dividuals and objects emitting stimuli.

The belief that wath the abandonment, as in modem physics, of
the ideal of complete precision, the more or less complex relations
which this yields proride a less intelligible picture thin we should
obtain by the introduction of h}pothetical electron paths is probably
due to our persistence in certain habitual w^ays of thinking.^

The unified language of physicalism confronts us wherever we
make a scientific prediction on the basis of laws, ^r^nen someone
says that if he sees a certain color he will hear a certain sound, or
vice versa, or when he speaks of the “red patch” next to the ‘'blue
patch,” which will appear under certain conditions, he is already
operating within the frame w'ork of physicalism. As a percipient he
is a physical stmciure: he must iocalke perception, e.g., in the cen-
; tral nervous system or in some other place. Only in this way can he
I make predictions and reach agreement with others and with himself
I at different times. Ever\^ temporal designation is already a physical
formulation.

; Science endeavors to transform the statements of everyday life.

I They axe presented to us as “agglomerations,” consisting of physical-
I istic and pre-physicalistic components. We replace them by the “uni-
fication” of physicalistic language. If one says, for instance, “the

! ^ 4. Cf. Concerning this, Philipp Frank, *'Der Charaktei der heutigen physikal-

; ischen Theorien,” Scientia, March 1931.

[ 288 ] OTTO NEURATH

screeching saw cuts through the blue wooden cube,” ‘‘cube” is
obviously an “intersensual” and “intersubjective” concept, equally
available for the blind and the deaf. If a man soliloquizes and makes
predictions, which he can himself control, he is able to compare
what he said of the cube when he saw it with what he communicates
in the dark when he touches it.

With the word “blue,” on the other hand, there is, at first, a
doubt as to how it is to be incorporated into the unified language.
It can be used in the sense of the rate of vibration of electromagnetic
waves. But it can also be used in the sense of a “field statement,”
meaning: when a seeing man (defined in a certain way) enters, as
a test body, the range of this cube, he behaves in a certain manner,
describable physicalisticaily; e.g., he says, “I see ‘blue.’ ” While
there may be doubt as to what people mean when they use “blue”
in colloquial speech, “screeching” would be chiefly intended as a
“field statement,” i.e., as an expression in which the auditor is al-
w’ays included. Closer consideration, however, reveals that “cube,”
“blue” and “screeching” are all words of the same type.

Let us attempt to follow up our analysis by giving a more exact
rendering of the above sentence, in accordance with physicaiism,
and reformulating it in a way that will make it more suitable for
prediction.

“Here is a blue cube.” (This formulation, like those which foi-
lov/, may be restated as a physical formula, in which the locus is
determined by means of coordinates.)

“Here is a screeching saw.” (The screeching enters into the
formulation, at first, only as vibrations of the saw and the air,
which could be expressed in physical formulae.)

“Here is a percipient man.” (Possibly a “field statement” could
be added indicating that under certain conditions the percipient en-
ters into a relationship with the physical blue and the physical
screeching.)

This perceiving may perhaps be divided into:

“Neural changes are occurring here.”

“Cerebral changes are occurring here in the perception area
and, perhaps, in the speech area also.” (It is immaterial for our
purposes whether these areas can be defined locationaliy or whether
they have to be defined structurally. Neither is it necessary to dis-
cuss whether changes in the speech area — the “speech-thought” of
the behaviorists — are connected with the larynx or laryngeal inner-
vation.)

Perhaps, in order to exhaust the physicaUstic meaning of this

'^^^dogy --andThysicaMsm [ 289 ]

seBtence, some£Miig more has still to be added, e.g., parties-
^iars coHcerniBg time, or positional coordinates; but the essential thing
'is that, in every case, the additions should be statements involving,
physick concepts.

^ It would be a mistake to suppose, because physical formulae
bf a very complex nature, which are still not fully at our disposal,
^ required for the computation of certain correlations, that, there-
fore, the physicalistic expressions of everyday life must also be
complex. Physicalistic everyday language will arise from existing
common speech, only parts of which will have to be discarded; others
will be integrated, while supplements will make up for certain defi-
ciencies. The occurrence of a perception will be, from the outset
more closely connected than hitherto with the observ^ation statement
and with the identification of the object. The analysis of certain
groups of statements, e.g., observation staiemenis, will proceed in
a different manner from before.

Children are capable of learning physicalistic every-day lan-
^age. They are able to advance to the rigorous symbolic language
of science and learn how to make successful predictions of all kinds,
without having to resort to “elucidations” supposedly functioning
as a meaningless introduction. It is a question of a more lucid mode
of speech, so formulated as to omit such expressions, for instance
as “illusion of the senses,” which create so much confusion. But
even though the physicalistic language has the capacity some day
to become the universal language of social intercourse, we must
continue to devote ourselves, for the present, to cutting away the
metaphysical appendages from the “agglomerations” of our lan-
guage and to defining physicalisticaliy ever\ihing that remains.
When the metaphysical cord is no longer present, much of what is
left may present itself as disconnected heaps. The further use of
such remnants would not be profitable, and a reconstruction would
be indispensable.

I We can often continue to make use of available “agglomerations”
by reinterpreting them. But caution is required here: men who are
ready enough to adjust their views, but at the same time comfort-
loving, frequently console themselves with the belief that a great
deal can be “systematically” reinterpreted. It is more than question-
able whether it would be convenient to continue to employ terms
like “instinct,” “motive,” “memory,” “world,” etc., attaching to
them a wholly unusual sense, which one may easily forget when one
goes on using these terms for the sake of peace. Certainly there are
^any cases in which a reconstruction of language is superfluous, or

[ 290 ] OTTO NEimXH

even dangerous. So long as one expresses oneself “approximately/"
one must guard against the desire to be, at the same time, excessively
subtle.

Since the views presented here are most nearly similar to the
ideas of Carnap, let it be emphasized that they exclude the special
“phenomenal” language from which Carnap seeks to derive the
physical language. The elimination of the “phenomenal” language,
which does not even seem to be usable for “prediction” — the essence
of science — ^in the form it has assumed up to now, will probably
necessitate many modifications in his system of concept construction.’®'
In the same way, we must exclude “methodological solipsism” (Car-
nap, Driesch), which seems to be an attenuated residue of idealistic
metaphysics, a position from which Carnap himself constantly at-
tempts to get away. The thesis of “methodological solipsism,” as
even Carnap would probably concede, cannot be scientifically for-
mulated. Nor can it be used to indicate a particular standpoint,
which would be an alternative to some other standpoint, because
there exists only one physicalism, and everything susceptible of sci-
entific formulation is contained in it.

There can be no contrasting of the “ego” or the “thinking per-
sonality,” or anything else with “experience,” “what is experienced,”
or “thought.” The statements of physicalism are based on statements
connected vdth seeing, hearing, feeling and other “sense perceptions”
(as physical events), but also with “organic perceptions,” which,
for the most part, are only roughly noted. We can, of course, close
our eyes, but we cannot stop the process of digestion, the circulation
of the blood, or the occurrence of muscular inneiv^ations. What
people are at pains to separate off as “the ego” are, in the language
of physicalism, events of this sort also, of which we are not informed
through our ordinary “external” senses. All “personality co-efficients”
which separate one individual from another are of a physicaiistic
kind!

Although the “ego” cannot be set off against either the “world
or “thinking,” one is able, without abandoning physicalism, to
distinguish statements about the “physicalistically described person,”
besides those concerning the “physicalistically described cube,” and
can, under certain conditions, make “observation statements,” thereby
creating a substitute for the “phenomenal language.” But careful
investigation will show that the mass of observation statements is
contained in the mass of physical statements.

* [This is a reference to the “Konstitutionssystem” elaborated by Carnap in his
book Der Logische Aufbau der Welt, Vide the Introduction p. 24. Ed.I

: §adohgy and Physicalism { 291 ]

- The protocol statements of an astronomer or a chronicler (ap-
'peanng as physical formulations) will, of course, be distinguished
from statements having a precisely determined position in the con-
'■ text of a physical system, despite the fact that between the two there
"are fiuid transitional stages. But there is no special “phenomenal”
as opposed to physicalistic language. Every one of our statements
■' Cm, from the very outset, be a physicalistic one — and it is this that
distinguishes what is said here from all the pronouncements of the
'^Vienna Circle/' which otherwise constantly stresses the importance
of predictions and their verification. Unified language is the language
of predictions, which are the very heart of physicalism.

In a certain sense, the doctrine here proposed proceeds from
a given condition of everyday language, which in the beginning is
essentially physicalistic, and, in the usual course of events, is grad-
ually developed in a metaphysical direction. Tnis forms a point of
contact with the “natural concept of the world” (“Nattirlicher
Weltbegriff”) in Avenarius. The language of physicalism is, sc to
speak, in no way new; it is the language familiar to certain “naive”
chfidren and peoples.

It is always science as a system of statements which is at issue.
Statements are compared with statements, not with “experiences,”
“the world,” or anything else. All these meaningless duplications
belong to a more or less refined metaphysics and are, for that reason,
to be rejected. Each new statement is compared with the totality
of existing statements previously coordinated. To say that a state-
ment is correct, therefore, means that it can be incorporated in this
totality. What cannot be incorporated is rejected as incorrect. The
alternative to rejection of the new^ statement is, in general, one
accepted only with great reluctance: the whole previous system of
statements can be modified up to the point where it becomes possible
to incorporate the new statement. Within unified science there is
important work to be done in making transformations. The defini-
tion of “correct” and “incorrect” proposed here departs from that
customary among the “Vienna Circle,” which appeals to “meaning”
and “verification.” In our presentation we confine ourselves always
to the sphere of linguistic thought. Systems of statements are subjected
to transformation. Generalizing statements, how^ever, as well as
statements elaborated by means of determinate relations, can be
compared with the totality^ of protocol statements.

Unified science thus comprehends a variety’ of types of state-
ments. So, for example, whether one is dealing with “statements about
^ality,” “hallucination statements,” or “untruths” depends on the

[ 292 J

degree to which one can otto neuratm

si—sisfiSsSss

perception centers; the latter evenfc ^ ‘^°^esponding events in the
for a hailucination If heqidt-c other hand essent* i

OBC can also infer,- P-epdoVcenSf

_ y> then one is dealing with “statp ^P^^^^ed, events outside the'
case, we can continue tn » i statements about realitv ” Tn tl-
f fitting i. f S fe

IS always compared with annrL^^l statement. A statement

statements, never with a “realitv ” or wth the system of

S?id b? ‘S’th : ‘‘^e’^Sr/Jof h^

fom Tc^ouJ? Physicaiism

physics, that is rS, ofVe'u''^^"^ S^sfSf

Many of the problems of the theo^^^fT^ meaningless piiras“=
rausformed into empirical ouesfiri ^ knowledge wili, perhaps C
accommodated in uSfied sSr ^ £y cS b1

Of how S' “StemSS “c'an ^e question

Pnysicaiistic constructioS “Two “ ohysicSs^ S

s^r “ <-X- u?f u?

“Tf A kTu ^“Oimands connected with nJi o^ bv a

If A behaves in such and sSh a wav 5 statements, e .

f’n,. . second. When tautoiories ar» statement is equivalew

‘■aintiug nachine" s„l “perimentaliy with , 0 , j .

could te fomSS ‘aidT“'1' ®-'' means of thi*:
“tS^-*^' machine would not even^^ °w automaticahy

two times red is hard.” ^hle to write the sentence

orientariom best combined with a he^ ■■ ■’ '

\Soci€fi0sy and Fhysicalism

: traced back to a past speech-thou<^ht or ^ ^

are only now evoking a reaction in speecb-tWhr-^'’^’”T^
of no essential importance. AU too often th7 h regard,

as if the refutation of some minor assertir^ discussion is conducted
somehow shaken the fu^JaSi behaviorists had
statements have a meaning i e can^hpn ^ physicalistic

There are no “elucidations” whiS are statements.

If someone wished to conceive of °i P^y®*=^sbc statements.
U,». like wtetfa and carS'aL

analysis. The physicalistic lanmiage^ilS^ °° ^°Sical

and Omega of all science. Thefe’ ^Pba

teside the “physical language ” no language”

side some other possible positioiT no sohpsism” be-

knowledge,” no new “Weltanschaunn° » P^?f0P^^y> no “theoiy of
only Unified Science, with its aS prSSiot "

HI. Sociology No “Moral Science”

just as h dSrSSthat^ftSSs^^r^ tbe behavior of machines
us about that of plants. SoL offts comnl
analyze even today, while the anaiw • statements we could

Here are .la^- S Ve 'raporarily elades

The .laws" of machines an red°c.?,f “f ““ “f"’

m this sphere, a law in terms of But even

often suffices, without recourse to measurement

s^e way, the laws of the animal ho? ®^^®onts. In the

there is no need to fall back on • often so formulated that

-here much has been Lr ftoTfh

structural laws, they have SfJn 2 ^ ^ investigation of macri
^ylarife mmaj ° «"h°n

Wn1 'i ‘£sc"7““^r

todamental diSere'La I* mSkes no

tons are involved. No mrnter wSlh f descrip-

s atispcal behavior of atomf investigatins the

P%ed in establishing corrS2?ns ? °^^fhods em!

afiove, all the law^of nntn ? ® same. As v/e s2

connected with one another ?f th21'^ ^

serving, as often as possible to2 ^be task of

groups of events. ’ individual events or certain

f i OTTO NEURATH

^ This does away, at the outset, with any fundamental division of
i^ed science, for instance, into the “natural sciences” and the
“moral sciences,” the latter being often referred to also in other
ways, e.g., “Kidturwissenschaften” (“sciences of culture”). The
theses by which it is intended to establish this division vary, but are
always of a metaphysical character, that is, meaningless. It is sense-
less to speak of different “essences” reposing “behind” events.
What cannot be expressed in terms of relations among elements
cannot be expressed at aU. It is consequently meaningless to go
beyond correlations and speak of the “essence of things.” Once it is
understood what the unified language of science really means, there
will be no more tdk of “different kinds of causality.” One can only
compare the organization of one field and its laws with the organiza-
tion of another, and ascertain, perhaps, that the laws in one field
are more complex than those in another, or that certain modes of
orgai^ation lacking in one are found in another; that, for example,
certain mathematical formulae are required in one case but not in
the other.

. ^ sciences” cannot be delimited from the “moral

sciences, it is even less p>ossible to make the distinction between the
philosophy of nature and the “philosophy of the moral sciences.”
Even leaving aside the fact that the former term is unsuitable because,
^ mentioned above, it still contains the word “philosophy,” by
“philosophy of nature” one can only understand a sort of introduc-
tion to the whole work of unified science. For how should “nature”
be distinguished from “non-nature”?

One cannot even adduce the practical exigencies of everyday
life or of the conduct of scientific investigations as justification for
this dichotomy. Is the theory of human behavior seriously to be
opposed to that of the behavior of all other objects? Is it seriously
intended that the theory of human societies should be fitted into one
discipline and the theory' of animal societies into another? Are the
natural sciences to deal with “cattle-breeding,” “slavery” and “war-
fare among ants, and the moral sciences with these same institutions
among men? If this is not meant, then the distinction is no sharper
than thm between different “scientific fields” in the older sense.

Or is there something to be said, perhaps, for the linguistic usage
according to which one simply speaks of “moral sciences” whenever
social sciences” are meant? But, to be consistent, one would have
to count the theory of animal societies together with the theory of
human societies as social sciences, and therefore as “moral sciences,”
an implication from which most people would recoil. And quite

f ^ Fhyskdism [ 295 ]

nmJeistaiidably so, for then where would be tli^ great cleavage con-
' c^ed beMnd all this, the cleavage depending on the maintenance of

■ the centuries-old theological habit of thought which divides up all

■ existence ' into at least two departments, e.g., a "‘noble’” and an
^Ignoble”? The dualism of “natural sciences” and “moral sciences,”
and the dualism of “philosophy of nature” and “philosophy of cul-
ture” are, in the last analysis, residues of theology.

The ancient languages are, on the whole, more physicalistic
than the modem. They are full of ma^cal elements, to be sure, but
above all they treat “body” and “soul” as simply two forms of
jnatter: the soul is a diminutive, shadowy body wMch issues from
the mouth of the individual at dleath. It is theology which first re-
places the contrast of “matter-soul” and “matter-body” with that of
“nos-matter-soul” and “matter-body,” as well as “non-matter-God”
and “matter-world,” adding a whole hierarchy of subordinate and
superior entities, natural and supernatural. The opposition of
“natural” and “supernatural” can be formulated only by means of
meaningless phrases. These phrases, because they are meaningless,
do not contradict the statements of unified science; neither are they
in accord with them. But they are certainly the cause of great con-
fusion. It is when it is asserted that these expressions are just as
meaningful as those of science that the trouble starts,®

What part the mental habit of theological dualism plays in the
creation of such dichotomies can perhaps be gathered from the fact
that as soon as one such division is discarded another easily estab-
lishes itself. The opposition of the “Is” and the “Ought,” which is
encountered especially among philosophers of law, may be men-
tioned here. In part, of course, this may be traced to the theological
opposition of “Ideal” to “Reality,” But the capacity of language for
fonning nouns facilitates all these- meaningless schemes. One can,
without violating syntactical rules, as serenely say “the Ought” as
“the sword.” And then people go on to make statements about this
“Ought” just as they would about a “sword,” or at least as they
would about the “Is,”

The “moral sciences,” the “psychical world,” the world of the
“categorical imperative,” the realm of Einfiihlung (empathy), the
reato of Verstehen (“the ‘understanding’ characteristic of the his-
torian”) — ^these are more or less interpenetrating, often mutually
substitutable, expressions. Some authors prefer one group of mean-
ingless phrases, some another, some combine and accumulate them^

5. Cf. Hans Haim, Vberfiussige Wesenheiten (Publications of the Verein Ernst
Mach, Vol. 11).

[ 296 ]

un,-i u neurath

°°^y margmal decorations of science

ZdTj Zir “Snence the entS

to of their pronouncements. Even if the practical effect of the

do^es on which the school of “moral sciences” is based are not
brt/^ confusion in empirical investigation wrought
y It IS not exaggerated, stUl, in the systematic establishment of

'‘““S' “ cl“e'p b1

take a^Seminerf"® practitioners of unified science to

cete^ed position against such distinctions; this is not a
matter for their arbitrary choice.

over these questions even among anti-
^ niinded thinkers, it is partly connected with the fact
that there does not exist sufficient clarity about the subject matter

wl- discipimes is concurrent with the separation

has nSf H ^ fields. This detachS

ISs eslv w“ efiminatsd by behaviorism, which, in

fiu essaj, w. always unoerstand in the widest sense. Onlv physica!-

s4em SeTth incorporated ffi'to Is

S sociologist makes predictions about human groups

iZluT-T ^ individual riTor

^ ^ .°“^/PP™P^^^cly be called social behaviorism

C^r conclusion is as follows: sociology is not, a “moral science” or'

st^d rUbm?’ “Geisteswissenschaft”)

‘ n?tnrJ f • opposition to some other sciences, called

unifie fsSZT ’ behaviorism, sociology is a part of

IV. Sociology as Social Beh.a.vioris.m

, in the same terms of men's paintin'’

housebuddmg religion, agriculture, poetry. And yet, it is maintained
agm and again that “understanding” human beings is fundamentaUv
Qifferent from merely” observing them and determining remilarities
^ “understanding,” of “empathy”

clahnS^hv closely connected with that traditionally

,. . ^ ® sciences.” We find here a resurrection of the

Principl^already eliminated on a previous

(experience,

possess the same empirical character.

Philosophical literature, especially the literature of the philosophy
ot history, frequently msists that without “empathy” and “under-

Physicalism [ 297 ]

'staacfiiig” it would be impossible to pursue historical studies or
comprehensively to arrange and describe human actions at all.

- “ How can we attempt to dispose in general of these obstacles
from the point of view of physicalism? It must be assumed from the
■ outset that the persistent asseverations of many sociologists and
philosophers of history concerning the unavoidability of recourse to
/Understanding’’ are also aimed at preserving the results of some
Ycry worthy scientific researches. Here, as so often elsewhere, it
may be a case of a not easOy disentangled combination of the dual-
istic habits of mind, originating in theolog}% and the actual procedure
of science. It will be apparent to anyone familiar with the monism
of unified science that even statements v>rhich are fully capable of
formulation in physicalistic terms have been presented in an un-
physicalistic form.

Sentences such as “I see a blue table in this room,” and “I feel
angry” do not lie far apart. The “I” is appropriately replaced by
some personal name, since all such statements may be applied to
anyone, and an ‘T-statement,” therefore, must be capable of being
asserted by someone else. Now we have: “There is a blue table in
this room,” and “There is anger in this man.” The discussions con-
cerning “primary” and “secondary” qualities are at an end when it
is realized that, in the last analysis, all statements about qualities
are of one type, only tautologies being excluded from the class of
such statements. Then all statements about qualities become physical-
istic statements. Besides these, there are tautologies, rules for the
combination and connection of statements. The propositions of
geometry can be interpreted as physicalistic statements or as tautolo-
gies, thereby removing many difficulties.

What, among other things, is characteristic of the sentence,
“There is anger in this man”? Its peculiarity is that it is open only to
inadequate analysis. It is as if someone were able to tell us, “Here is
a severe storm” without being in a position to state in what manner
it was composed of lightning, thunder, rain, etc., nor yet whether
he arrived at his discoveries by means of his eyes, ears or nose.

When one speaks of anger, organic perceptions are made use
of. Changes in the intestinal tract, internal secretions, blood pressure
and muscle contraction are essentially equivalent to changes in the
eye, ear or nose. In the systematic construction of behaviorism, a
man’s statement, “I am angry” is incorporated into physicalism not
only as the reaction of the speaker, but also as the formulation of
his “organic perceptions.” Just as, from the enunciation of “color
perceptions,” one can infer physicalistic statements about retinal

[ 298 ]

and other events, so from assertions about anger ie
ateut organic perceptions,” one can derive phvsicalistic
about “intestinal changes,” “changes in b£,d SS? « ef 4?
nomena which become known to others often only by means of 4ch
statements. This may be appended as a suppleminrrfm^^
^cussions on ti^ subject, where the fidl value^of statements ab4t

"0

requires this experience of “organic
fterceptions m order to have empathy with another person^ h{«

pnysica^Uc statements concemmg one’s own bodv in tnoHr,,.
physicateac statements aboM another's is complei* in

PoiaS”^i'^°^^’ throu^out makes this sort of “extra-

such “xtensions mduction leads us constantly to

m-nts''S4 ?Kf'nt?^® s^e prmciple is involved in making state-
ments about Ae other side of tne moon on the basis of our exirien'-
^ncemmg the side which faces us. That is to say, orS^Ju^

by h S2i“Sat'4?d P^ysi^stic language if one means no m4e
persons nn th<a' h inferences about physical events in other

on^s^^ concerning organic changes in

on.s own tody. Wnat is involved here, as in so many other cieT

?oielatif the usual attempt at estabhshiag

S S “ regard to ^y

ot th.se .vents leaves, to be sure, much to be desired One would

come very- close to the actual state of agairs if one were to say that
±e moral sciences are, above aU, the sciences in which correlatbns

for inadequately described and

names are available.

oathv” concepts of “understanding” and “em-

everything in them that is usable in a physical-

4en7s' Thrill .st^ten^ent about order, exactly as in aU
..ien..s. The alleged distinction between “natural sci4ices” and

■ Sv" ST’’ “ T“ '« coLmSSseS

non-^xisMnt. **“ >>“"■ "i* understaneiing as well, is

formulations are encountered
Aey are subjected to systematic formulation, physicalistic statements

tnatnio- ^ matter of mdiference for the position here

maintamea wnether certain individual theses of Watson’s Pavlov’s
or others are upheld or rejected. What is essenS °s 'tirody

md Fhysicaiism [ 299 ]

physiccdisticaiiy formulated correlations be employed in the descrip-
tion of living things, whatever may be observed in these things.

It woxjld be misleading to express this by saying that the distinc-
tion of “psychical” and “corporeal” no longer existed, but had been
feplaced by “something neutral.” It is not at all a question of a
"something,” but simply of correlations of a physicaiistic character.
Only insufficient analysis can lead anyone to say something like:
"It cannot yet be .ascertained whether the whole sphere of the
‘psychical’ really admits of physicaiistic expression. It is, after all,
possible that here and there another type of formulation is required,
ie., concepts not physicaiisticaiiy definable.” This is the last remnant
of belief in a “soul” as a separate form of being. When people have
observed a running clock and then see it stop, they can easily make
use of the capacity of language for creating nouns, and pose the
problem, "‘Where has the 'movement’ gone to?” And after it is
explained to them that all that can be known about the clock is to
be discovered through analysis of the relations between its parts
and the surroundings, a sceptic may still object that, although he
understands that speculation about the “movement” is pure meta-
physics, he is stiU doubtful whether, for the solution of certain com-
plicated problems relating to the operations of clocks, physicaiism
entirely suffices.

Without meaning to say that every sociologist must be trained
in behaviorism, w^e can still demand of him that, if he wishes to
avoid errors, he must be careful to formulate all his descriptions of
human behavior in a wholly straightforward physicaiistic fashion.
Let him not speak of the “spirit of the age” if it is not completely
clear that he means by it certain verbal combinations, forms of
worship, modes of architecture, fashions, styles of painting, etc. That
he undertakes to predict the behavior of men of other ages on the
basis of his knowledge of his own behavior is wholly legitimate, even
if sometimes misleading. But “empathy” may not be credited with
any peculiar magical power transcending ordinary induction.

With inductions in this or that field, it is always a question of a
decision. This decision may be characteristic of certain human groups
or of whole ages, but is not itself logically deducible. Yet induction
always leads, within the physicaiistic sphere, to meaningful state-
ments. It must not, for this reason, be confused with the interpolation
of metaphysical constructions. There are many who concede that
they formulate metaphysical constructions, i.e., that they insert
meaningless verbal combinations, but nevertheless will not fully
appreciate the damage caused by such a procedure. The elimination

, OTTO NEURATH

J ote Py'Mosy. as well as to

of the trances essences. People often expect from the priest

SSr® """'■‘"“a 'SSfZ“er.t

statements to the r“aim of rormulated observation-

S!:nz:“ -

mundaboat wa ““e° S“ .aZZ'T?””', “i’)'

given data. This is clear from ^ ^ ' J ''

follows from X. and Z fohows from y' 5°f '^‘^""^tion: if Y

from X Even if Y»r,u j ^ ^ ^ follows immediately

conceptions I arril^ afthe^f

tions Lverthel^s- <iV,°t ^ Pianetari- orbits, this world of concep-

Js3is?2£S£5f”" -

stoSf s^L^Ve^v.^^^^ tf

possible to take into account hnth™t investigated. It is

by “external” stimuli and those caSS'S- “

“within” Iivin<j things (<- a th» .rh-^v, ° r ^“^^^omous changes

fi^n toves..ia.e-S disto.Sor„rSil! ZSZ’ S

6- Otto Neurath, Empirische Souologie, p. 57 .

- -Sodology and Fhysicalism [ 301 ]

iiiEtteaced by anything external, as well as the decomposition of a
chemical compound through the addition of oxygen. Whether analo-
gies to the disintegration of radium play a role within the human body
need not be discussed here.

Sociology does not investigate purely statistical variations in
animal or, above all, human groups; it is concerned with the connec-
tions among stimuli occurring between particular individuals. Some-
times, without analyzing these connections in detail, it can determine
under certain conditions- the total behavior of groups united by
common stimuli, and make predictions by means of the laws ob-
tained. How is “social behaviorism,” unimpeded by metaphysics,
to be pursued? Just as every other actual science is pursued. Naturally,
in investigating human beings certain correlations result which are
not encountered in the study of stars or machines. Social behaviorism
attains to laws of a definite type peculiar to itself.

To pursue physicalistic sociology is not to transfer the laws of
physics to living things and the groups they form, as some have
considered feasible. It is passible to discover comprehensive socio-
logical laws, as well as laws for narrower social areas, without
having recourse to micro-structure, and thus being able to base these
sociological laws on physical ones. Whatever sociological layvs are
discovered without the aid of physical laws in the narrower sense are
not necessarily altered by the addition of a subsequently discovered
physical substructure. The sociologist is completely imimpeoed in
his search for laws. The only stipulation is that he must always
speak, in his predictions, of structures which are given in space
and time.

V. Sociological Correlations

It is as little possible in sociology as in other sciences to state
at the outset on the basis of purely theoretical considerations what
correlations can be employed with a prospect of success. But it is
demonstrable that certain traditional endeavors meet with consistent
failure, while other methods, adapted to discovering correlations,
are not at present sufficiently cultivated.

Of what type, then, are sociological correlations? How does one
arrive, with a certain degree of reliability, at sociological predictions?
In order to be able to predict the behavior of a group in a certain
respect, it is often necessary to be acquainted with the total life of
the group. Variations in the particular modes of behavior distinguish-
abie in the totality of events, the construction of machines, the

t"

n

i

^ -

m

li

I

[ 302 ] OTTO NEUXATH

erection of temples, the forms of marriage, are not “autonomously”
calculabie. They must be regarded as parts of the whole that is
investigated at any given time. In order to know how the construction
of temples will change in the future, one must be familiar with the
methods of production, the form of social organization, and the
modes of religious behavior in the period which is taken as the
starting point; one must know the transformation to which all of
these together are subject.

Not all events prove equally resistant to being employed in such
predictions. Given certain conditions, from the mode of production
of a historical period one can often roughly infer the next phases
in the development of the mode of production and the form of social
organization. Then one is in a position to attempt with some success
to make further predictions about religious l^havior and similar
matters with the aid of such previous predictions. Experience shows
that the reverse procedure, on the other hand, meets with failure,
i.e., it does not seem possible to derive predictions about the mode
of production from predictions about religious behavior alone.

But, whether we direct our attention to the methods of production,
to religious behavior, to the construction of buildings, or to music,
we are always confronted with events which can be physicalistically
described.

Many of the social institutions of an age can be properly accounted
for only if their distant past is known, w^hile others might, so to
speak, be devised at any time given the appropriate stimuli. There
is a certain sense in which the presence of camions acts as a stimulus,
producing armed turrets b}^ way of reaction. The dress coats of our
day, on the other hand, do not represent a reaction to dancing, and
it is only with difficulty that they would be newly devised. But it is
comprehensible to us that at some time in the past, a man dressed
in a long-skirted coat became the inventor of the dress coat when
the skirts of his coat flapped up while he was riding. The coherence
between established customs is different in the two cases.

Just as one must be informed about the type of coherence in
order to be able to make predictions, so one must know whether
the detachment of a certain institution or segment from a social
complex is easy or difficult, and whether, in the case of loss, it can
be replaced. The state, for example, is a highly stable complex whose
operations are, to a considerable extent, independent of the change-
over of personnel: even if many judges and soldiers w’^ere to die,
there would be new ones to take their place. A machine, on the

F^ysicdism [ 303 ]

& ■ does not generally replace wheels which have been re-
:iiioved from it.

is a wholly physicalistic question to what extent the existence
-'“of 'specially conditioned individuals, deviating from the norm, assnres
tie stability of the state structure. The related question of the degree
to which such significant individuals are replaceable must be treated
separately. The queen bee assumes a special position in the hive,
but when a queen bee gets lost, there is the possibility that a new
om will emerge. There are always, so to speak, latent queens. How
is this in the case of human society?

The extent to which predictions about social complexes can be
made without taking into consideration the fate of certain particularly
pronainent individuals is entirely a concrete sociological question.
It is possible to maintain, with good reason, that the creation of
bourgeois Europe, once the machine system had imparted to the
modem capitalistic transformation its characteristic hue, w^as pre-
dictable at the end of the eighteenth century. On the other hand, one
could hardly have predicted Napoleon’s Russian campaign and the
burning of Moscow. But it would, perhaps, be valid to say that if
Napoleon had defeated Russia, the transformation of the social
order would have proceeded in the same way as it did in fact pro-
ceed. Even a victorious Napoleon would have had to countenance
the old feudalism of Central Europe to a certain degree and for a
certain time, just as, on another occasion, he re-established the
Catholic Church.

The extent to which prediction is possible, or relates to particular
individuals, in no way affects the essence of social behaviorism. The
movements of a leaf of paper in the wind are equally unpredictable,
and yet kinematics, climatology and meteoroiog>^ are all highly
developed sciences. It is no part of the essence of a developed
science to be capable of predicting every individual event. That the
fate of a single leaf of paper, say, a breeze-blown thousand dollar
bill, may especially interest us, is of little concern to scientific investi-
gation. We need not discuss here whether a chronicle of the “acci-
dental” paths of leaves in the wind could eventually lead to a theory
of the paths of leaves. Many of the views associated with Rickert
and allied thinkers yield no scientific laws even where they can be
physicalistically interpreted.

. Sociolo^, like every science, tracks down correlations which
can be utilized for predictions. It seeks to lay down its basic con-
oeptions as unambiguously and clearly as possible. One may attempt,

[ ] OTTO NEURaTH

for instance, to define groups tlirough ''commercium'' and ‘'con-
nubtum/^ One ascertains who trades with whom, or who marries
whom. There may emerge clearly distinguishable areas of concentra-
tion, together with poorly occupied border areas. And then one
could investigate the conditions under which such concentrations
vary or even disappear. To discover the correlation of such areas
of concentration with the processes of production obtaining at their
respective periods is obviously a legitimate sociological task, which
might be of importance for the tfaeoiy of “classes.”

One can investigate, for instance, under what conditions matri-
archy, ancestor worship, agriculture and similar institutions arise,
at what point the founding of cities begins, or what correlations
exist between systematic theology and other human activities. One
can also ask how the administration of justice is determined
by ^ social conditions, although it is questionable whether such
limited divisions will exhibit sufficient law-like regularities. It
may well be, for instance, that certain events occurring outside the
field of law must be added to those involved in the administration
of justice, if relations statable as laws are to be found.

one group recognizes as law^, another may regard as outside
the legal order. Thus, only correlations among men’s statements
concerning the “law,” or between their behavior and their statements
can be established. But it is not possible, without special preliminary
work, to contrast “legal events” as such with other events.

It IS doubtful whether simple sociological correlations can be
- :■ determined between the allowed interest rate, on the one hand, and

i standard of living of a period, on the other: whether simpler

relations do not appear when the “allowed interest rate” and ‘*pro-
^^t>ited usury” are taken together. Thus, the modes of behavior on

w

■Mk

ill!' '

It

which unfavorable “legal” and “ethical” judgments are passed could
be incorporated into sociology, and the judgments themselves could
be included. These disciplines are in every sense branches of sociolog}’,
but they are quite different from the “ethics” and “jurispmdence”
which are commonly cultivated. The latter yield few or no socioiogicai
correlations. They are predominantly metaphysical, or, where free
of metaphysics, their methodology and arrangement of statements
can only be explained as residues of theology. In part, they yield
purely logical deductions, the extraction of certain injunctions from
others, or of certain conclusions from given legal assumptions. But
all this lies outside the sphere of ordered correlations.

VL Ethics and Jurisprudence as
Remnants of Metaphysics

la its origiii, etMcs is the discipline which seeks to determine the
of divine injunctions. It attempts to find out, by means of a
togicai combination of commandments and prohibitions of a universal
kind, whether a given individual act is commanded, permitted or
forbidden. The “casuistry” of Catholic moral theologians has ex-
elaborated this type of deduction. It is quite obvious that
the indeterminateness of divine injunctions and the ambiguity of
their meaning preclude any genuine scientific method. The great
expenditure on logical deductions was, so to speak, squandered on
a worthless object, even though, historically, it prepared the way
for the coming logicizing period of science. If the God who issues
the commands, as well as events in heaven and hell (which was
located by many theologians at the center of the earth) are pfaysicai-
istically defined, then one is dealing with a non-metaphysical dis-
cipline, to be sure, but a highly uncritical one.

But how is a discipline of “ethics” to be defined once God
is eliminated? Is it possible to pass meaningfully to a “command-
in-itself,” to the “categorical imperative”? One might just as well
talk of a “neighbor-in-himself without any neighbors,” or of a
“son-in-himself, who never had a father or mother.”

How is one to distinguish certain injunctions or modes of be-
havior in order to make possible “a new ethics within the context of
physicalism”? It seems to be impossible. Men can form joint resolu-
tions and conduct themselves in certain ways, and it is possible to
study the consequences of such actions. But what modes of behavior,
what directives is one to distinguish as “ethical,” so that correlations
may then be set up?

The retention of an old name is based on the view that there is
something abiding to be discovered, which is common to the old
theological or metaphysical and the new empiricist disciplines. When
all metaphysical elements, as well as whatever physicaiistic theological
elements it may contain, have been eliminated from ethics, there
remain only statements about certain modes of human behavior or
the injunctions directed by some men to others.

One could, however, also conceive of a discipline pursuing its
investigations in a wholly behavioristic fashion as part of unified
science. Such a discipline would seek to determine the reactions
produced by the stimulus of a certain way of living, and whether such

and Pkysicalism

[ 305 ]

^ 1 OTTO NEUBATH

ways of living make men more or less happy. It is easy to
a aoroughly empirical “felicitology” (Felicitologie) , on a behavior-
istic foundation, which could take the place of traditional ethics.

But a non-metaphysical ethics usually seeks to analyze, in one
way or another, men’s “motivations,” as if this provided a suitable
^oundwork for relations statable as laws. What men assert about
the ‘reasons” for their conduct, however, is essentially more de-
pCTdent on contingencies than the general run of their behavior.
When the general social conditions of a given period are known, the
behavior of whole ^oups can be far more readhy predicted than the
rabonale which individuals wiU adduce for their conduct. The modes
of conduct will be defended in very different fashions, and very few

moreover, wiU note the correlation between the social situation and
average conduct.

These “conflicts of motivations,” for the most part metaphysically
ormulated, are avoided by an empirical sociology, which is" intent
upon xruitful work. This is the case with Marxism, the most pro-
aucbve semiology of the present day. It endeavors to establish mr-
relations between the social situation and the behavior of entire
Classes, so that it can then account for the frequently changing verbal
sequences w^ch ^ supposed to “explain the motivation” of the
scientifically law-afaidmg actions which are conditioned in this vray.

Ma^m, m its aescriptions of relations expressible as laws,
makes as hdle use as possible of what men assert about themselves,

« consciousness,” their “ideoio©-,” it is related
to those schools of psychologj^” which accord to the “unconscious”
prominent role. Thus it is that psychoanalysis
and indiMdual psychology, by virtue of the fact that they confute and
f motivational psychology of consciousness (today quite
oee), prepare the way for modem empirical sociolosi', which
s^ics, m the spmt of unified science, to discover correlations'between
actions and the factors that condition them.

And even if psychoanalysis and individual psychology in their

fhfr metaphysical expressions, never-

tii,.less, through their emphasis on the relation between behavior and
Its unconscious preconditions, they are precursors of the behavior-
istic^ay of thmkmg ^d of sociological methodology.

■ ^ permissible to ask whether a certain manner of livin*’

happiness, since “happiness” can be described
whoUy behavionstically; it is valid to ask on what depend the de-
mands which masses of men make of one another, what new demands
are set, what modes of behavior will emerge in such a situation.

and Fhysicalism [ 307 ]

?'fC3ain^ modes of behavior in this regard are often fimdamentafly
'"^"divetgCEt) A1 these are legitimate sociological formulations of
^problems* Whether it is advisable to characterize them as “ethical”
• ‘i^cd cot be decided here.

'■ The case of “jurisprudence” is a similar one, when it is iiader-
' "^ 0 od as something odier than the sociology of certain social phe-
Domeiia* But when it takes up the task of establishing whether a
^tem of claims is logically consistent, whether certam conclusions
of the statute books can be harmonized with certain observation-
statements about legal practice, we are concerned with purely logical
investigations. When we determine that the rules of a chemist are
logically compatibie, we have not yet entered the sphere of the
science of chemistry. In order to pursue chemistry, we must establish
correlations between certam chemical events and certain tempera-
tures, and other such things. The fact that, despite their essentially
metaphysical preliminary formulations, the representatives of cer-
tain schools of jurisprudence can produce something logically and
scientifically significant does not prevent our rejecting these formu-
lations, as, for example, the following:

The thinking of mathematical or logical laws is a psychical act, but
the object of mathematics — that which is thought of — is not something
psychical, neither a mathematical nor a logical ‘"soul,” but a specific
intellectual reality. For mathematics and logic abstract from the psy-
chological fact of the thinking of such an object. In the same way the
state, as the object of a special mode of thought to be distinguished
from psychology, is a distinctive reality, but is not the fact of the thinking
and willing of such an object. It is an ideal order, a specific system of
norms. It resides not in the realm of nature — the realm of physical-
psychical relations — but in the realm of spirit. The state as obligating
authority is a value or — so far as the proposiiional expression of value
is established — a norm, or system of norms. As such, it is essentially
difierent from the specifically real fact of the conceiving or wOling of
the norm, which is characterized by indifi*erence to value.'^

Formulations of this type are connected with similar ones on
“ethics” and related disciplines, without any attempt having been
made to discover how the term “objective goals” is to be fitted into
miified science, and without indicating any observation-statements
through which “objective goals” as such might be determined. Again:

K the “general theory of the state” asks what the state is and how it is,
1* e., what its possible basic forms and chief components are, politics

7. Kelsen, Allgemeine Staaislehre, pp. 14 ff.

^ OTTO NEUitATH

“substocture” to another group as “superstructure” (“historica]
materialism” ^ a social physicalistic theory), it proceeds throush-
out its operations 'within the confines of social beha'viorism. What k
mvolved here is no opposition of the “material” to the “spiritual ”
1. e., of essences” with “different types of causality.” *

TOe coming decades may be concerned in growing measure with
the discovery of such correlations. Max Weber’s prodigious attemot
to demonstrate the emergence of capitaUsm from Calvinism clearly
shows to how great an extent concrete investigation is obstructed
by metaphysical fonnulations. To a proponent of social behaviorism

It seems^ at once quite natural that certain verbal sequences ^the

formulation of cert^ divine commands— should be recognized as
dependent on certain modes of production and power situations.
But It does not seem very plausible that the way of life of vast
numbers of human beings occupied with trade, industiy and other
matters, should be determined by verbal sequences of individual
th^logians, or by the deity'’s injunctions, always very vaguely worded
which the theologians transmit. And yet Max Weber was committed
to tlus point of view. He sought to show that from the “spirit of

Calyimsm was bom the “spirit of capitalism” and with it the
capitalist order.

^ A Catholic theologian, Klraus, has pointed out that such an over-
estimation of the influence of theological formulations can only be
explained by the fact that he ascribed to spirit a 'Sort of “magical”
effect. In the work of Weber and other thinkers, “spirit” is regarded
as very closely bound up with words and formulae. Thus we under-
assiduous quest for crucial theological formulations
of individual Calvinists, in which the origins of crucial capitalist
formulations might be sought. The “rationalism” of one sphere is
to spnng from that of the other. That theological discourses and
wnhngs possess such enormous powers is a supposition which would
be formally possible within a physicalistic system. But experience
proves otherwise. In company with the Marxists, the Catholic the-
ologian mentioned above points out the fact that theological subtle-
ties exercise little influence on human behavior, indeed, that they
are scanty known to the average merchant or professional man. It
would be much more plausible to suppose that in England, for
example, merchants opposed to the royal monopoly, and usurers
desirmg to take interest at a higher rate than the Church of En g lan d
peimtted, readily gave their support to a doctrine and a part\^
wtech turned against the Church and the crown allied with the
Church. First the behavior of these men was, to a considerable ex-

i &^dology ^ Physicalism [ 311 ]

capitalistically oriented — Ihm they became Calvinists. We should
expect to find, in accordance with all our experience of theological
diKlrines at other times, that these doctrines were subsequently re-
and adapted to the system of production and commerce. And,
Kraus further shows, in opposition to Weber, that those theological
formulatioiis which are “compatible” with capitalism did not appear
; until later, while Calvinism in its ori^al form was related rather
; to the dogmas of the anti-capitalist Middle Ages. Webers metaphysi'^

, cal starting’-point impeded his scientific work, and determined un--
■ favorably his selection of observation-statements. But without a
suitable selection of observation-statements there can be no fruitful
sdentific work.

Let us analyze a concrete case in somewhat greater detail. With
what is the decline of siaveiy^ in the ancient w^orid connected?

Many have been inciined to the \iew that Christian doctrine and
the Christian way of life eSected the disappearance of slavery, after
the Stoic philosophers had impaired the conception of slaver>^ as an
eternal institution.

If such an assertion is meant to express a correlation, it is
natural to consider, in the first place, whether or not Christianity
and slavery are found together. It is then seen that the most oppressive
forms of slavery appear at the begiiming of the modem era, at a
time when Christian states are eveiywhere expanding their power,
when the Christian Churches are vigorous above ail in the colonies.
Because of the intervention of Catholic theologians motivated by
humanitarian considerations, the preser%^ation of the perishing Indian
slaves of America was undertaken through the importation of sturdier
Negro slaves brought to that continent in shiploads.

It would really be necessar}^ to define in advance with a greater
degree of precision v»^hat is meant, on the one hand, by “Christian,”
and, on the other, by “slaver\'.” If the attempt is made to formulate
the correlation between them with greater clariiy, it must be said
that statements of a cenain type, religious behavior, etc., never
appear in conjunction with the large-scale ownership of slaves. But
in this connection, it would be necessary^ to lay down a definite mode
of application. For a man can be a “slave” from the “juristic” stand-
point, and, simultaneously, a “master” from the “sociological” point
of view. Sociological concepts, how^ever, may be linked only with
other sociological concepts,

“Christian dogma” is an extraordinarily mdeterminate concept.
Many theologians have believed it possible to demonstrate, from
the Bible, that God has condemned the Negroes to siaveiyr: when

{ ] OTTO NEURATH

Ham treated his drunken father Noah irreverently, Noah cursed him
and declared that he and his descendants were to be subject to his
brothers Shem and Japheth and their descendants. Still other theo-
logians have sought to discover in Christian doctrine arguments
against slavery.

It is evident that the sociologist advances much further when
he delimits a certain system of men, religious acts, dogmas, etc.,
and then notes whether it comes into being in conjunction with cer-
tain modes of social behavior. This is, of course, a very rough pro-
cedure. The attempt must be made to discover not only such simple
correlations, but also correlations of greater complexity. Laws must
be combined with one another, in order for it to be possible to
produce certain predictions.

Some sociological “laws” are valid only for limited periods, just
as, in biology, there are laws about ants and about lions in addi-
tion to more general laws. That is to say, we are not yet in a position
to state precisely on what certain correlations depend: the phrase
“historical period” refers to a complicated set of conditions which
has not been analyzed. Much confusion is due to the opinion of
some analytical sociologists that the laws which they had discovered
had to possess the same character as chemical laws, i.e,, that they
had to hold true under all conceivable earthly condiiions. But sociol-
og}^ is concerned for the most part w^itb correlations^ valid for limited
periods of time. Marx was justified in asserting that it is senseless
to speak of a universal iaw^ of population, as Malthas did. But it is
possible to state which law of population holds for any given socio-
logical period.

When, for the purpose of clarifying the question, “How does the
decline of slavery come about?” one analyzes the confiici between
the Northern and Southern States over the freeing of the slaves,
one is confronted by a conflict between industrial and plantation
states. The emancipation inflicts serious injury on the plantation
states. Shouldn’t we expect a connection between the freeing of the
slaves and the processes of production? How^ is such a notion to be
made plausible?

One attempts to determine the conditions under which slavery
offers the slave-owner advantages, and the conditions under w^hich
the contrary is the case. If those masters w^ho free their slaves are
asked why they do so, only a few will say that they oppose slavery
because it does not yield sufficient advantages. Many will inform
us, without hypocrisy,, that they have been deeply impressed by
reading a philosopher who championed the slaves. Others will de-

ond Physicalism [ 313 ]

in detail their conflicting motives, v41i perhaps explain that
slavery would really be more advantageous to them, but that the
" ‘-•'‘■desire to sacrifice, to renounce property, has led them, after a long
%7*iliiier* conflict, to the difficult step of freeing their slaves. Anyone
• ^ ‘ aa:nsto^^^ to operate in the spirit of social behaviorism will, above
‘ ■ all^ fceep in mind the very complicated ‘'stimulus” of the way of
" "• - life based on slave-owning, and then proceed to investigate the
^reaction” — retention or freeing of the slaves. He will employ the
■-results of this inquiry to determine how far theological doctrines
concerning the emancipation of slaves are to be recognized as “stim-
ulus,” how far as “reaction.”

; ' ' If it is shown that relatively simple correlations can be estab-

lished between the effects of slaveiy^ on the masters’ tenor of life
and the behavior of the master toward the liberation of slaves, and
that, as against this, no simple correlaiions can be laid down between
the doctrines of the time and the behavior of the slave-owners,
then preference will be given to the former mode of investigation.

Thus there wall be examined under various conditions the rela-
tionship betv/een hunting and slaver}% agricuiiure and slaver\\ manu-
facture and slavery. It wffil be found, for example, that the possession
of slaves generally offers no advantage where there are sufficiently
numerous free workers who eagerly seek employment in order to
avoid start^ation. Columella, a Roman agrarian writer of the later
period, bluntly says, for example, that the employment of slaves is
disadvantageous to anyone who drains fever sw’amps in the Cam-
pagna: the sickness of a slave means loss of interest, while his
death results in loss of capital He goes on to say that it is possible,
on the other hand, to obtain free workers on the market at any
. time, and that the employer is in no way burdened by their sick-
ness or death.

When serious fluctuations in the business situation occur, entre-
preneurs find it desirable to be in a position to drop free workers;
slaves, like horses, must continue to be fed. When one reads in
Strabo, therefore, that in antiquity pap\Tus shrubs in Egypt were
already being cut dowm in order to maintain the monopoly price,
one understands that the universal employment of free labor could
not be far away.

t-U.y ' - Tho conditions which led to the fluctuating tendencies of early
k ' economic institutions can likewise be investigated. Cor-

relation is added to correlation. It is seen that “free labor” and “the
■r -destruction of commodities” seem to be correlated under certain
. . conditions. This is equally true of “plantation slavery” and “a con-

[ 314 ] OTTO neukatb

slant iii,arket.” One can view the Civil War as a conflict between the
indestrial North, which was not interested in slaver}^ and the cotton-
produdng agrarian South, and thereby be able to make extensive
predictions.

This does not mean that the religious and ethical opponents
of slavery were lying when they said that they directly rejoiced in the
emancipation of the slaves, but not in the increase of industrial
profits which ensued in the North. That such a desire for the free-
ing of the slaves could develop at this time and find so rich a satis-
faction is something which the empirical sociologist could deduce,
in broad outline, from the total economic situation.

The methods used in the elaboration of a theory of agricultural
economics have also been applied by several writers (theologians
among them) in the construction of a wholly empiiicsd theory of
the "‘employment of natives,’’ yielding all types of correlations.^ In
combination with other relations expressible as laws one can make
all sorts of predictions concerning the fate of slaver}’ in particular
countries and territories.

The distribution of grain to freemen but not to slaves, during
the later history of Rome, offered slave-owners an additional motive
for freeing their slaves. The former master could then re-employ the
freedman at a lower cost, and also use his support at elections. It
is likewise easy to understand how, during the decline of Rome, the
system of the ‘'coloni” and serfdom emerge through the regression
of early capitalistic institutions. In order to undertake an enterprise
with slave labor, one had to have at one’s disposal extensive financial
resources, since both workers and implements of production had
to be purchased. Under a regime of free labor, the purchase of
tools was sufficient. The system of the “coloni” required no invest-
ment at all from the owner, who was assured of dues of all kinds.
The “free” workers w^ere forced by the whole social order to labor
— the death penalty was imposed for idleness — ^while each slave had
to be disciplined by his own master. The master had to protect the
health and life of his slave, to care for him just as he had to care
for a horse or a bullock, even when it was unruly.

We see how, by means of such analyses, correlations are estab-
lished between general social conditions and certain modes of be-
havior of limited human groups. The “statements” which these
groups make about their own behavior are not essential to these
correlations; they can often be added with the help of additional

9. Cl Otto Neurath, “Probleme der Kriegswinschaftslehre,” Zeitschrift fur die
gesamten Staatswissenschaften, 1914, p. 474.

: Sociology and Physicdism [ 315 ]

'^^mflations. It is above aU in MaEtism that empirical sociology is
pursued in this way.“

A system of empirical sociology in the spirit of social behavior-
'issis as it has been developed above all in the United States and the
0.S.S.R-, would have to direct its inquiries primarily to the typical
^reacdons^’ of whole groups. But significant historical movements
axe also often measured or evaluated without such analysis. And it
may further be shown that through the development of certain in-
stitutions, through the increase in a certain magnitude, a reversal is
produced which causes further changes to take a whoEy different
direction. The primitive “idea of progress,” that every magnitude in-
creases indefinitely, is untenable. One must consider the whole sys-
tem of sociological magnitudes in all its complexity, and then note
what changes are predictable. One cannot infer from the growth of
large cities up to the present time that the process will continue
approximately the same. Rapid growth is especially apt to release
stimuli leading to a sudden cessation of growth and perhaps to the
reconstitution of many small centers. The expansion of capitalist
large-scale industry and the emergence of the proletarian masses
dependent on those industries can lead to a situation where the whole
capitalist mechanism moves through a series of economic crises
towards its ultimate dissolution.

\1II. Possibilities of Prediction

It is possible to state the extent to which predictions can be
successfully made within the sphere of social behaviorism. It is evi-
dent that its various ''predictions i.e., its scientific theories, are
sociological events essentially dependent on the social and economic
order. It is only after this is understood that it becomes cie ar, for
example, that under certain conditions certain prediciions either do
not emerge at all, or cannot be elaborated. Even when an individual
believes that he divines the direction of further successful investiga-
tion, he can be prevented from finding the collaboration required
for sociological research by the indifference, or even the opposition,
of other men.

The approach of social changes is difficult to notice. In order
to be able to make predictions about events of a new' type, one must
usually possess a certain amount of new experiences. It is often the
changes in the historical process that first give the scientist the

example, Etiore Ciccotti, Der Untergang der Sklaverei in Altertum
(German translation by Oda Oiberg), Berlin, 1^10.

*■ ■* OTTO NEURaTH

necessa^ data for further investigations. But since sociological in-
TCStigatioi^ ako play a certain role as stimuli and instruments in
the organization of living, the development of sociology is very
closely bound up with social conflicts. Only established schools of
sociology, requirmg social support, can master, by means of coUective
labor, the masses of material which must be adapted to a stricter
formulation of correlations. This presupposes that the powers which
fmance such work are favorably inclined towards social behaviorism
This IS in general not the case today. Indeed, there exists in the
nilmg classes an aversion to social, as well as to individual, behavior-
ism which is much more than a matter of a scientific doubt, which
would be comprehensible in view of the imperfections of this doc-
tnne. The opposition of the ruling circles, which usuaUy find support
in the umversities of the capitalist countries, is explained sociologi-
cally, above aU, by the fact that empirical sociology, through its
non-metaphysical attitude, reveals the meaninglessness of such ex-
pressions as “categorical imperative,” “divine injunction,” “moral
Idea, superpersonal state,” etc. In doing this it undermines imnor-
d^nnes which are useful in the maintenance of the prevailino
order. The proponents of “unified science” do not defend one worldt
view arnong other world-views. Hence the question of tolerance
cannot be raised. They declare transcendental theology to be not
taise, out meaningless. Without disputing the fact that powerful in-
spiration and cheering and depressing effects, can be associated with
meamngiess doctnnes, they can in practice “let seven be a holv
numter, smce they do not harass the supporters of these doctrines,
ut they^camot ^ow that these claims have any meaning at all,
owever i den, i.e., that they can confirm or confute scientific

emen s. Even if such reasoning by the pure scientist leaves meta-
physics and theology undisturbed, it doubtlessly shakes the reverence
lor txiem whicii is frequently demanded.

i^l the metaphysical entities whose injunctions men endeavored
to obey, and whose “holy” powers they venerated, disappear. In
toeir place there stands as an empirical substitute, confined within
the bounds of purely scientific formulations, the actual behavior of

operate as empirical forces on individual
men. That groups of men lend strength to individual men pursuing
certain modes of action and obstruct others pursuing different modes'^
beha^^orism^°^ which is wholly meaningful in the 'context of social

tehaviorist, too, makes commands, requests and
reproaches, but he does not suppose that these utterances, when

- Sociology md Fhysicalism [317]

-'connected with propositions, can yield a system. Words can be
employed Eke whistles, caresses and whiplashes; but when used
' la this w^ay, they can neither agree with nor contradict propositions.

' An injunction can never be deduced from a system of propositions!

■ '7 ' This is no “limitation” of the scientific method: it is simply the
result of logical analysis. That injunctions and predictions are so
frequently linked follows from the fact that both are directed to
the future. An injunction is an event which it is assumed wEl evoke
certain changes in the future: A prediction is a statement which it
is assumed will agree with a future statement.

The proponents of “unified science” seek, with the help of laws,
to formulate predictions in the “unified language of physicaEsm.”
This takes place in the sphere of empirical sociology through the
development of “social behaviorism,” In order to attain to more
useful predictions, one can immediately enminate meaningless verbal
sequences by the use of logic. But this is not sufficient. There must
follow the elimination of all false formulations. The representatives
of modern science, even after they have effected the elimination of
metaphysical formulations, must stiff dispose of false doctrines, for
example, astrolog}^ magic, etc. In order to liberate someone from
such ideas, the universal acknowledgment accorded to the rules of logic
does not, as with the elimination of meaningless statements, suffice.
One must, if one wishes to see one’s own theoiw prevail, create the
groundwork v/hich will lead people to recognize the inadequacy of
these theories, which, while ''also physicalistic/' are uncritical.

The fruitfulness of social behaviorism is demonstrated by the

establishment of new correlations and by the successful predictions
made on the basis of them. Young people educated in the spirit of
physicalism and its unified language will be spared many of the
hindrances to scientific work to v/hich we are still at present sub-
jected. A single individual cannot create and employ this successful
language, for it is the product of the labor of a generation. Thus,
even in the form of social behaviorism, sociolog}- will be able to
formulate vaUd predictions on a large scale only when a generation
trained in physicalism sets to work in all departments of science.
Despite the fact that we can observe metaphysics on the increase,
there is much to show that non-metaphysical doctrines are also
spreading and constantly gaining ground as the new “superstructure”
erected on the changing economic “substructure” of our age.^^

11. Cf. Otto Neurath,
onist, October 1931.

‘Physicalism, the Philosophy of the Vienna Circle,*’ The

V j

Analytical Philosophy

15

^ ^-.;

Philosophy

BY FRANK P. RAMSEY

Philosophy must be of some use and we must take it seriously; it
must clear our thoughts and so our actions. Or else it is a disposition
we have to check, and an inquiry to see that this is so; i.e. the chief
proposition of philosophy is that philosophy is nonsense. And again
we must then take seriously that it is nonsense, and not pretend,
as Wittgenstein does, that it is important nonsense!

In philosophy we take the propositions we make in science and
e^-eiyday life, and try to exhibit them in a logical system with primi-
tive terms and definitions, etc. Essentially a philosophy is a system
of definitions or, only too often, a system of descriptions of how
definitions might be given.

I do not think it is necessary to say with Moore that the defi-
nitions explain what we have hitherto meant by our propositions,
but rather that they show how we intend to use them in future.
Moore would say they were the same, that philosophy does not
change what anyone meant by “This is a table.” It seems to me
that it might; for meaning is mainly potential, and a change might
therefore only be manifested on rare and critical occasions. Also
sometimes philosophy should clarify and distinguish notions previ-
ously vague and confused, and clearly this is meant to fix our future
meaning oniy.^ But this is clear, that the definitions are to give at
least our future meaning, and not merely to give any pretty way of
obtaining a certain structure.

I used to worry myself about the nature of philosophy through
excessive scholasticism. I could not see how we could understand

This extract is taken from Ramsey’s The Foundations of Mathematics, copy-
1931 by Routiedge and Kegan Paul, London, with whose permission it is here
rtiainted.

!• But in so far as our past meaning was not utterly confused, philosophy will
natur^y give that, too. E.g. that paradigm of philosophy, Russell’s theory of
descriptions.

V- -i

2

[ 322 ]. FRANK P. RAMSEY

a word and not be able to recognize wiietiier a proposed definition
of it was or was not correct. I did not realize tbe vagiieness of the
whole idea of understanding, the reference it involves to a multitude
of performances any of which may faM and require to be restored.
Logic issues in tautoio^es, mathematics in identities, philosophy in
definitions; all trivial but all part of the vital work of clarifying and
organmng our thought.

If we regard philosophy as a system of definitions (and elucida-
tions of the use of words which cannot be nominaliy defined), the
things that seem to me problems about it are these:

( 1 ) What definitions do we feel it up to philosophy to provide,
and what do we leave to the sciences or feel it unnecessary to give
at an?

(2) WTaen and how can we be content v^ithout a definition but
merely with a description of how a definition might be given?
[This point is mentioned above.]

(3) How can pMlosopMcal inquir}* be conducted Vrithout a per-
petual petitio principii?

(1) Philosophy is not concerned with special problems of defi-
nition but only with general ones: it does not propose to define
particular terms of art or science, but to settle e.g. problems which
arise in the definition of any such term or in the relation of any
term in the physical world to the terms of experience/

Terms of art and science, however, must be denned, but not
necessarily nominally; e.g. we define mass by explaining how^ to
measure it, but this is not a nominal definition; it merely gives the
term “mass” in a theoretical structure a clear relation to certain ex-
perimental facts. The terms we do not need to define are those
which we know we could define if need arose, like “chair,” or those
which like “clubs” (the suit of cards) we can translate easily into
visual or some other language, but cannot conveniently expand in
words.

(2) The solution to what we called in (1) a “general problem
of definition” is naturally a description of definitions, from which
we learn how to form the actual definition in any particular case.
That we so often seem to get no actual denniiions, is because the
solution of the problem is often that nominal definition is inappro-
priate, and that what is wanted is an explanation of the use of the
symbol.

But this does not touch what mav be supposed to be the real

msophy'- [ 323 ]

ilBcMiy iHider tMs head (2); for what we have said applies only
^ mrtks case in which the word to be defined being merely described
tmated as one of a class), its definition or explanation is
of course, merely described, but described .in such a way that
the actual word is given its actual definition can be derived,
~ But 'there are other cases in which the word to be defined being
-even, we are given in return no definition of it but a statement that
its meaning involves entities of such-and-such sorts in such-and-
ways, i.e. a statement which, would give us a definition if we had
names for these entities.

As to the use of this, it is plainly to fit the term in connection
with variables, to put it as a value of the right complex variable;
and it presupposes that we can have variables without names for all
their values. Difficult questions arise as to whether we must always
be able to name all the values, and if so what kind of ability this
means, but clearly the phenomenon is in some way possible in con-
nection with sensations for which our language is so fragmentary.
For instance, “Jane’s voice” is a description of a characteristic of
sensations for which we have no name. We could perhaps name it,
but can we identify and name the different inflections of which it
consists?

An objection often made to these descriptions of definitions of
sensory characteristics is that they express what we should find on
analysis, but that this kind of analysis changes the sensation ana-
lyi&d by developing the complexity which it pretends merely to dis-
cover. That attention can change our experience is indubitable, but
it seems to me possible that sometimes it reveals a pre-existing com-
plexity (i.e. enables us to symbolize this adequately), for this is
compatible with any change in incidental facts, anything even except
a creation of the complexity.

Another difficulty with regard to descriptions of definitions is
that if we content ourselves with them we may get simply nonsense
by introducing nonsensical variables, e.g. described variables such

“particular” or theoretical ideas such as “point.” W^e might for
glance say that by “patch” we mean an infinite class of points;
if so we should be giving up philosophy for theoretical psychology.
For in philosophy we analyze our thought, in which patch could not
be replaced by infinite class of points: we could not determine a
particular infinite class extensionaily; “This patch is red” is not
short for “a is red and b is red etc. . , where n, b, etc., are points.
(Pow would it be if just a were not red?) Infinite classes of points

[ 324 ] FRANK P. RAMSEY

could only come in when we look at the mind from outside and
construct a theory of it, in which its sensor}^ field consists of classes
of colored points about which it thinks.

Now if we made this theory about our own mind we should have
to regard it as accounting for certain facts, e.g. that this patch is red;
but when we are thinking of other people’s minds we have no facts,
but are altogether in the realm of theoiy^ and can persuade ourselves
that these theoretical constructions exhaust the field. We then turn
back on our own minds, and say that what are really happening
there are simply these theoretical processes. The clearest instance of
this is, of course, materialism. But many other philosophies, e.g.
Carnap’s, make just the same mistake.

(3) Our third question was how we could avoid pernio principii,
the danger of which arises somewhat as follows:

In order to clarify my thought the proper method seems tc be
simply to think out with myself “¥/hat do I mean by that?” ‘‘What
are the separate notions invoived in this term?” “Does this really
follow from that?” etc., and to test identic of meaning of a pro-
posed definiens and the definiendum by real and hypothetical ex-
amples. This we can often do without thinldng about the nature of
meaning itself; w^e can tell whether w^e mean the same or difierent
things by “horse” and “pig” without thinking at all about meaning
in general. But in order to settle more complicated questions of the
sort w^e obviously need a logical structure, a system of logic, into
which to bring them. These we may hope to obtain by a relatively
easy previous application of the same methods; for instance, it
should not be difficult to see that for either not-p or not-^^ to be true
is just the same thing as for not both p and q to be true. In this
case we construct a logic, and do all our philosophical analysis en-
tirely unselfconsciously , thinking all the time of the facts and not
about our thinking about them, deciding what we mean without any
reference to the nature of meanings. [Of course we could also think
about the nature of meaning in an unseliconscious way; i.e. think
of a case of meaning before us without reference to our meaning
it.} This is one method and it may be the right one: but I think it
is wrong and leads to an impasse, and I part company from it in
the following w^ay.

It seems to me that in the process of clarifying our thought we
come to terms and sentences which we cannot elucidate in the ob\i-
ous manner by defining their meaning. For instance, variable hTOO-
theticals and theoretical terms we cannot define, but we can explain
the way in which they are used, and in this explanation we are forced

*1

not only at the objects which we are talking about, but at
mental states. As Johnson would say, in this part of logic
'cannot neglect the epistemic or subjective side.

; -Now this means that we cannot get clear about these terms and
without getting clear about meaning, and we seem to get
situation that we cannot understand e.g. what we say about
time and the external world without first understanding meaning
and yet we cannot understand meaning without first understanding
certainly probably the external world which are involved

in it So we cannot make our philosophy into an ordered progress to
- a goal, but have to take our problems as a whole and jump to a
simultaneous solution; which will have something of the nature of
z hypothesis, for we shall accept it not as the consequence of direct
ar^iment, but as the only one we can think of which satisfies our
several requirements.

Of course, we should not strictly speak of argument, but there
is in philosophy a process analogous to “linear inference” in which
things become successively clear; and since, for the above reason,
we cannot carry this through to the end, we are in the ordinary posi-
lion of scientists of having to be content with piecemeal improve-
ments: we can make several things clearer, but we cannot make
anything clear.

I find this self-consciousness inevitable in philosophy except in
a very^ limited field. We are driven to philosophize because we do
not know clearly what we mean; the question is always “What do
I mean by jc?” And only ver\^ occasionaiiy can we settle this with-
out reflecting on meaning. But it is not only an obstacle, this necessity
of dealing with meaning; it is doubtless an essential clue to the truth.
If we neglect it I feel we may get into the absurd position of the
child in the following dialogue: “Say breakfast.” “Can’t.” “W’'hat
can’t you say?” “Can’t say breakfast.”

But the necessity of self-consciousness must not be used as a
Justification for nonsensical hypotheses; we are doing philosophy not
theoretical psychology, and our analyses of our statements, whether
about meaning or anything else, must be such as we can understand.

The chief danger to our philosophy, apart from laziness and
woolliness, is scholasticism, the essence of which is treating what is
vague as if it w^ere precise and trying to fit it into an exact logical
' ' P^tfigory^ A typical piece of scholasticism is Wittgenstein’s view that
. ^ our everyday propositions’ are completely in order and that it is
impossible to think illogically. (This last is like saying that it is im-
possible to break the rules of bridge because if you break them

[ 326 ] FRANK P. RAMSEY

you are not playing bridge but, as Mrs. C. says, not-bridge.) An-
other is the argumentation about acquaintance with before leading
to the conclusion that we perceive the past. A simple consideration
of the automatic telephone shows that we could react differently to
AB and BA without perceiving the past, so that the argument is
substantially unsound. It turns on a play with “acquaintance” which
means, first, capacity to symbolize and, secondly, sensory percep-
tion. Wittgenstein seems to equivocate in just the same way with
his notion of “given.”

16

fc' ' , y"'-' y

Philosophical Arguments

BY GILBERT RYLE

Robin Gec«ge Collingwood held this Waynflete Chair for a

lamentably brief time. Yet his literary productivity during this short
: . period was immense. The time is not yet ripe for me to attempt to
offer a critical evaluation of these contributions to philosophy, nor,
even were I competent, should I on this occasion offer an apprecia-
tion of Ms originality as an historian. He would himself, I think,
have desired recognition chiefly for his thoughts on the philosophy
of history. About these thoughts, therefore, I submit, with humility
and diffidence, a few reflections.

There are many branches of methodical inquiry into the different
departments of the world. There are the mathematical sciences, the
several natural sciences, and there are the humane or human studies
of anthropolog}^, jurisprudence, philosophy, the linguistic and lit-
erary studies, and iiistor}^ which last embraces in one way or an-
other most of the others. There are also many disciplines which
teach not truths but arts and skills, such as agriculture, tactics,
music, architecture, painting, games, navigation, inference, and sci-
entific method. All theories apply their own several principles and
canons of inquir}’' and all disciplines apply their own several prin-
ciples and canons of practice. These princ'iples were called by Pro-
fessor Coilingw'ood their “presuppositions.” In other words, all em-
ploy their own standards or criteria by which their particular exercises
are judged successful or unsuccessful.

— Now it is one thing mtelligently to apply principles; it is quite
pother thing to step back to consider them. A scientist who ceases
or a moment to try to solve his questions in order to inquire instead
why he poses them or whether they are the right questions to pose
^^ssesT^the time to be a scientist and becomes a philosopher. This

, Inaugurai lecture at Oxford, copyright 1946 by the Clareodon

uxtord, it is reprinted here with the kind pennission of the author and pub-

[ 328 ] GILBERT RYLE

duality of interests may, as histoiy shows, make him both a good
philosopher and a better scientist. The best philosophical theories of
mathematics have come from mathematicians who have been forced
to try to resolve internal puzzles about the principles of their study,
a philosophical exercise which has sometimes led to the origination
of new mathematical methods and has often led to the origination
of illuminating philosophical views. Ever\^ genius is the inventor of
new methods and he must therefore be some sort of a critic of
principles of method.

Professor Collingwood was an historian who was puzzled about
the canons of historical research. He wanted not only to explain
certain historical processes and events but also to elucidate what
sort of a thing a good historical explanation would be. Nor was this
a purely domestic or technological interest. For to see what is an
historical explanation, is, among other things, to see how it diners
from a chemical, mechanical, biological, anthropological, or psycho-
logical theoiy^ The philosopher may, perhaps, begin by wondering
about the categories constituting the framework of a single theoiy^
or discipline, but he cannot stop there. He must tiy^ to co-ordinate
the categories of ail theories and disciplines. The problem of “Man's
place in Nature” is, roughly, the problem of co-ordinating the ques-
tions which govern laboratoiy researches with the questions gov-
erning the researches prosecuted in libraries. And this xo-ordination
is done neither in libraries nor in laboratories but in the philosophers
head.

Professor Collingwood saw more clearly, I think, than did his
most eminent predecessors in the philosophy of history that the ap-
pearance of a feud or antithesis between Nature and Spirit, that is
to say, between the objectives of the natural sciences and those of
the human studies, is an illusion. These branches of inquiiy are not
giving rival answers to the same questions about the same world;
nor are they giving separate answers to the same questions about
rival worlds; they are giving their own answers to different questions
about the same world. Just as physics is neither the foe nor the
handmaid of geometr\% so history, jurisprudence and literary studies
are neither hostile nor ancillary to the labor ator}' sciences. Their
categories, that is, their questions, methods and canons are different.
In my predecessor's word, they work with different presuppositions.
To establish this point it is necessary to chart these differences. This
task Professor Collingwood died too soon to complete but not too
soon to begin. He had already made that great philosophic advance
of reducing a puzzle to a problem.

TJ^opMced Arguments [329 ]

Professor CoUingwood kept himself aloof from the sparring

the shadow-boxing by which academic philosophers ordinarily
''sti^cgtheii their muscles and discharge their humors. What we lost
this abstention was compensated by the world’s gain. For he
less for the eyes of his professional associates than for those
■ ||jg intelligent citizens of the entire republic of letters. In conse-
' queoce he achieved a style of philosophical writing and, I believe,
diction, which at its frequent best is on a level with the higher ranges
of English philosophic prose. •

The Problem

.. PMlosophers have in recent years given much consideration to
the nature, objectives and methods of their owm inquiry. This in-
terest has been due partly to a certain professional hypochondria,
since the conspicuous progress made by other studies has induced
in philosophers some nervousness about the scale of their own suc-
cesses. P^y, also, it has been due to the application of modem
logical theor}' to the processes of the mathematical and the inductive
sciences, which has automatically led to its application to philosophy.
The exposition of the logical credentials of different sorts of scientific
conclusions has posed in a bright if painful light the corresponding
question about the foundations of philosophical doctrines.

My object is to exhibit the logical structure of a t3me of argu-
ments which are proper to philosophical thinking. It makes no dif-
ference whether these arguments are used polemically in controversies
between philosophers or peaceably in privaie philosophical reflection.
For arguments are effective as weapons only if they are logically
cogent, and if they are so they reveal connections, the disclosure of
which is not the less necessar}' to the discover}^ of truth for being
also handy in the discomfiture of opponents. The love of truth is not
incongruous with a passion for correcting the erring.

Philosophical arguments are not inductions. Both the premises
and the conclusions of inductions can be doubted or denied without
absurdity. Observed facts and plausible hypotheses have no more
illustrative force in philosophy than is possessed by fictions or guesses.
Nor have either facts or fancies any evidential force in the resolution
of philosophical problems. The evidential force of matters of fact
is only to increase or decrease the probability of general or particular
hypotheses and it is absurd to describe philosophical propositions as
relatively probable or improbable.

On the other hand philosophical arguments are not demonstra-

>edient to distinguish the strong reductio ad absurdum
■eductio. The latter form is used in some of Euclid’s
He demonstrates the truth of a theorem by deducing
Victory consequences which conflict with the axioms
' with consequences drawn from them. It should be
^argument proves only either that the required the-
the axioms are true or that both are false, that is,
ctoiy' of the required theorem is not compatible with
strong reduction consists in deducing from a propo-
)lex of propositions consequences \^ch are incon-
other or with the original proposition. It shows (to
ishion which will have to be amended later) that a
Jgitimate because it has logically absurd corollaries,
under investigation is shown to be not merely false

arguments of this type belong to philosophy it is
i that It would be proper for a dissentient philos-
imolish this or any other philosophical assertion
radictions latent in it. I am not trying to prov'e
! of argument are proper to pIiilosophyT
leration it wiH seem that arguments of the t 3 me
um can have only a destructive effect. They may
Qolishing silly theories and thus possess, besides
ty of defeating opponents, the useful one of clear-
bsequent constructive theory. But it will be felt
5 can result in the erection of a new dwelling. I
^ such objection by showing that (to use anoSier
> ad absurdum arguments are neither more nor
e threshmg operations. Or, to change the picture
wm be maintained that philosophical arguments
3 have something in common with the destruction-
leers discover the strength of materials. Certainly

gilbert RYLE

uclidean type, namely deductions of theorems from
;ulates. For philosophy has no axioms and it is de-
king its start from postulates. Otherwise there could
ihilosophical doctrines as there are alternative geom-

f argument which is proper and even proprietary' to
he reductio ad absurdum. This argument moves by
•aihctions or lo^cal paradoxes from its material. It
this discussion to show how this is possible and why

Arguments

f331]

stretch, twist, compress, and batter bits of metal until they
it is just by such tests that they determine the strains
^ttft&Ji'the metal ^ withstand. In somewhat the same way, philo-
^phical arguments bring out the logical powers of the ideas under
"iaftstigation, by JBxing the precise forms of logical mishandling under
K - 1 - which they refuse to work.

s Logical Powers of Propositioss

i^ery proposition has what will here be called certain “logical
- ‘ powers”; that is to say, it is related to other propositions in various dis-
lo^cal relationships. It follow^s from some as a consequence
and it implies others. It is incompatible with some and merely com-
patible with others. It is e\idence strengthening or weakening the prob-
ability of ulterior h}qx>theses. Further, for any logical powers pos-
sessed by a given proposition it is always possible to find or invent
an inde^te range of other propositions w'hich can be classed with
it as having analogous logics powers or. as it is commonly put, as
of the same logical form.

For the rules of logic are general. \'’alid arguments exhibit pat-
terns which can be manifested equally %vell by collocations of any
other propositions of the same logical family. Formal logicians learn
to extract the logical skeletons of propositions in virtue of which
these and any other propositions embodying the same skeletons can
function as premises or conclusions of parallel valid arguments.

Now when people are using or considering a given proposition
they cannot then and there be attending to all its logical powers.

cannot in one moment be considering it and all the valid argu-
ments into which it might enter and an lUc fallacious arguments
into which it might be improperly coerced. At best their grasp is
adequate for them to be able to thinl: out some of these logical
powers if they have occasion to do so. Many of the logical powers
3f a proposition are not noticed at all in the routines of workaday
thinking and of these a proportion balSes discovery’ even when the
thinker is concentrating his whole ioteliectual strength upon the search
for them. Thus people can correctly be said to have only a partial
grasp of most of the propositions that they consider. They could
be taken by surprise by certain of the remoter logical con-
of their most ordinary propositions.

None the less, though people’s understanding of the proposidoiis
that they use is in this sense imperfect, there is another sense in which
their understanding of some of them may be nearly or quite complete.

GILBERT RYLE^

For they may have learned from practice or instruction all their
logical powers which govern the limited uses to which those proDosi.
tons are ordinarily put. A boy leams quickly how to use such proDoI
sitions as3 X3 = 9or London is due north of Brighton without ever
makmg the arithmetical or geographical mistakes which would be
evidence of an imperfect grasp of such propositions. He does not
know the rules governing the logical behavior of these propositions
but he knows by wont their logical course down a limited set of
familiar tracks. ^

The fact that people, however intelligent, never achieve a com-
p ete appreciation of all the logical powers of the propositions that

important consequences
It should be noticed that even mastery of the techniques and the
theory' of formal logic does not in principle modify- this situation. The
extraction of the logical skeletons of propositions does not reveal
the logical powers of those propositions by some trick which absolves
the lopcian from thinking them out. At best it is merely a summary
formulation of what ms thinking has discovered.

_ When several different propositions are noticed having something
in common (and wnen this common feature or factor is^not itself a
constituent proposition) it is convenient and idiomatic, though haz-
ardous, to abstract this common factor and call it (with excentions)

Thus men learn to fasten on the idea of
i.a I y or me concept of price as that which is common to a rapoe
of propositions in which persons are affirmed or denied to be mortal

T said to cost so much or to be exchan'-'c-

able at such and such rates. Later they learn to isolate in the same
rnanner more abstract ideas like those of existence, impiicatioh. dutv.
species, mind, and science. ^ ^

In the early days of logical speculation these ideas or conc^nks
were construea as being proper parts or substantia! bits, an assemblage
Oi two or more of which was supposed to constitute a proposition.

W i styled “terms.- This erroneous theoiw

has been the source or a multitude of damaging confusions. The truth
K ihat what we label “ideas” or “concepts” are abstractions from the
tnSc'% propositions of which they are common factors or fea-
nf n™ summarily of the family

fector Tt t rosembling each other in respect of this common

t ctor. Statements about ideas are general statements about familie-:

OI propositions.

A natural but disastrous corollary drawn from the erroneous
doctrme of tenns was the assumption that the rules of logic govern the

■ '^^^pkicd Arguments { J

^oas "between propositions but have little or no bearing upon
factors. It was, indeed, early discerned that there are logically
differences of type or category^ betvv^een different classes of
■{rl' ^ ^Ideas,” or “concepts,” but the original and traditional classi-
"'ftaffon of a few of these types lent nothing to and borrowed nothing
the study of the rules of inference. (True, certain rules of in-
. iatMCC were :seeii to be interlocked with the concepts all, some, and
But no 'niche was found even for these ideas in the table of
'■•'categories ofxoncepts.)

fact the distinction between the logical types of ideas is iden-
. ; ^ tical with the discrimmation between the logical forms of the propo-

’ sirions from which the ideas are abstractions. If one proposition has
factors of different types from those of another proposition, those
propositions are of different logical forms and have different sorts of
logical powers. The rules governing the conjunctions of propositions
' is valid arguments reflect the logical consiinitions of their various
abstractible factors and features. There are as many upes of terms
as there are forms of propositions, just as there are as many uphill
as downhill slopes.

It is therefore both proper and necessaiy to speak not only (at
one level of abstraction) of the logical powers of propositions, but
also (at a higher level of abstraction) of the logical pov/ers of ideas
or concepts. Of course, a description of the logical powers of a given
idea is neither more nor less than a description of certain of the logical
powders of all propositions similar to one another in having that idea
as an abstractible common factor.

As people’s understanding of the proposiiicns that they use is
always imperfect, in the sense that they never have realized and
never could realize ah the logical powers of those propositions, so
their grasp of ideas or concepts is necessarily incomplete. The risk
always exists that confusion or paradox will arise in the course of
any hitherto untried operations with those ideas.

; The Sources of Logical Paradoxes

j . Concepts and propositions cany^ with them no signal to indicate
^ ^ logical types to which they belong. Expressions of the same gram-

y . ' ^srical patterns are used to express thoughts of multifarious logical

I ■ , Men naturally, therefore, tend to be blind to the fact that dif-

ideas have different logical powers or at least they tend to
& -j ' varieties of logical types as being few in number. Even

ii, P^^^pbers have assumed for over two thousand vears that Aris-

[ 334 ] GILBERT RYLE

totle’s inventory of ten such t5rpes was exhaustive if not over-
elaborate.

What happens when a person assumes an idea to be of one
logical type when it really belongs to another? — ^when, for example^
he assumes that the ideas large or three have logical powers similar
to those of green or merr/l The inevitable consequence is that naive
Intellectual operations with those ideas lead directly to logicaEy m-
tolerable results. Concepts of different types cannot be coerced into
similar logical conduct. Some sort of contradiction arises from the
attempt and this, in fortunate cases, compels the thinker to turn
back in his tracks and try to change his treatment of the outraged
concept.

The Diagnosis and Core of Paradoxes

Here there begins a new sort of inquiiy^ the deliberate attempt
to discover the real (as distinct from the naively anticipated) logical
powers of ideas. The logical absurdities which betray the origirial
type-confusions give an intellectual shock and set a theoretical prob-
lem, the problem of determining with method and with definitive
checks the rules governing the correct manipulation of concepts.

This task can be metaphorically described as the charting of
the logical powers of ideas. The metaphor is helpful in a number
of ways. People often know their way about a loc^ty w^hiie quite
unable to describe the distances or directions between different parts
of it or between it and other familiar localities. They may knov; a
district and still be perplexed when approaching it by an unaccus-
tomed route or in a strange light. Again they may know the district
and still give descriptions of it which entail that two different build-
ings are in one place or that one building lies in two different direc-
tions from a given object.

Our workaday knowledge of the geography of our ideas is in
similar case — even of those ideas with which we can operate eE-
cientiy in the daily tasks in which w^e have been drilled. This worka-
day knowledge is knowledge but it is knowledge without system and
yf'ithout checks. It is knowledge by wont and not knowledge by rules.

There is another respect in which the metaphor of maps is use-
ful. Surveyors do not map single objects like the village church.
They put together in one map all the salient features of the area:
the church, the bridge, the railway, the parish boundar}^, and per-
haps the contours. Further, they indicate how this map joins the
maps of the neighboring areas, and how^ all are co-ordinated with

[335 ]

Phihsophicd Arguments . , . ] 1

of tbe compass, the lines of latitude and longitude and
^S^of measuremLt. Any error in surveying results m a carto-

^^Tre^°ution of type-puzzles about the logical powers of ideas
A mauds an analogous procedure. Here too the problem is not to
^Sit separately^ the locus of this or that single idea but to deter-
mine the cross-bearings of all of a galaxy of ideas belongmg to ^

or contiguous fields. The problem, that is, is not to anatomize
S^^litary cS:ept, say, of liberty but to extract its lopcal poweK
as these bear on those of law, obedience, responsibihty, loyalty, go -
emment and the rest. Like a geographical survey a philosop^c^
sSSy is necessarily synoptic. Philosophical problems cannot be

fwipfii or soivs(i ipi6Csrtio2.i. ,

^^°^TOs description of the inquiry into the logical powers of ideas
as bein<' analogous in some respects to a geographical survey is, ot
course, "of iUustrative utility only within narrow limits. In one m-
portant respect among many others the analog' breaks down. The
TOrrectness of a geographical survey is established by two major
sorts of checks; the presence of a cartographical contradiction proves
that the survey is erroneous but visual observations are positive evi
deuce of its veracity. In the extraction of the lo^cal powers of ideas
there is no process directly corresponding to visual observation.
Hence the primacy in philosophical reasoning or the reauctio ad
absurdum argument. The object to which this phiiosopmcai destmc-
tion-test is applied is the practice of operating with an laea as n it
belonged to a certain category, that is as if it had powers correspon -
ing to those of an accepted model. InitiaUy this practice is naive and
unoremeditated. Sometimes it is deliberately recommended and
adopted. In this case the destruction-test is being apphed to a

philosopher’s theor}'. .

The earliest philosophical problems are set by contrauictions m-
advertently encountered in the course of non-phiiosophical thinking.
As every new theory^ begins certain new concepts coine aHlO -.nr
rency, concepts which are cardinal not merely to its conclubions Dut
even to its questions. Being new their logical powers are still un
explored, and being new^ they are unthinkingly credited with
powers similar to those of ideas the discipline of which is familiar.
Paradoxical consequences flowing from conventional operations upon
them reveal that they have characters of their own. So must hoi^es
Have startled their first masters by their non-bovine shape and be-
havior.

When the deliberate attempt is made to find the harness which

[ 336 ] GILBERT RTX.E

wiil fit refractory concepts, the method is adopted of consciously
looking for further logical paradoxes and contradictions. The rules
governing the logical conduct of an idea are imperfectly grasped so
long as there remain unexamined chances that it is still being mis-
handled. Absurdities are the original goad to philosophical thinking’
they continue to be its scalpel.

This process can without injustice to the genealogy of the word
be called “dialectical,” though there seems no reason to constrict
the process within the symmetrical confines of the hallowed double-
entry method often associated with its employment. It is also the
procedure followed, though not explicitly prescribed, by those who
prefer to describe philosophy as being the clarification of ideas, the
analysis of concepts, the study of universals and even the search for
definitions.

An Objection

At this point it is necessary to face and resolve a difficulty — in-
deed a contradiction — ^which threatens to make nonsense of every-
thing that I have said. Its emergence and its resolution may serve
as an illustration of my general position.

It has been said that philosophical problems arise from a tend-
ency of propositions (as we inadvertently handle them) to generate
absurd consequences. But if the consequences of a proposiiion are
absurd that proposition is absurd and then there can be no such
proposiiion. It is absurd to say that there are absurd propositions.
It is logically impossible for there to be a proposition of such a
type that there could be no propositions of that type. It seems to
follow that the reductio ad absurdum can never be applied, though
the argument establishing this point itself exemplifies that pattern.

The solution is that expressions and only expressions can be
absurd. Only of a given expression such as a sentence, therefore,
can it be said that it cannot be construed as expressing a proposition
of a certain logical constitution or, perhaps, a proposition of any
logical constitution. This is what the reductio ad absurdum does. It
discloses that a given expression cannot be expressing a proposition
of such and such a content with such and such a logical skeleton,
since a proposition with certain of these properties would conflict
with one with certain of the others. The operation by which this is
established is in a certain fashion experimental or hypothetical. If
the expression is expressing a proposition at all, it cannot be express-
ing one analogous in these respects to certain familiar propositions

^J^^phkd Arguments [ 337 ]

In |||0se respects to others, since the corollaries of part of the
' ^^thcsis are at variance with those of another part. It is an hypo-
argument of the pattern known as ponendo tollem. In ex-
famine cases it may establish that the expression cannot be expressing
; •- pj^position of any pattern; in milder cases it proves only that it
^nhot be expressing a proposition of certain specified patterns.

■ For examples, take the two statements ‘‘Numbers are etemaf’
^ ^‘Time began a million years ago.” Both are linguistically regular
sfatements but the latter sentence expresses no proposition. It tries
to say what cannot be significantly said, viz. that there was a mo-
ihent before which there w^as no possibility of anything being before
^ything else, which contains a patent contradiction. The former
.sentence is nonsensical if construed as expressing a proposition of
one type but not if construed in another way. If it is construed as a
terse way of saying that numbers are not temporal things or events
or, better, that numerical expressions cannot enter into significant
expressions as subjects to verbs with tenses, then what it says is
true and important. But if it is construed, as childlike people have
construed it, as saying that numbers, like tortoises, live a very long
time — and in fact however old they get, they cannot die — then it
could be shown to be absurd. It is nonsense when construed as an
item of biology but true wben interpreted as an application of the
theory of logical types to arithmetical ideas. ,

Reductio ad absurdum arguments, therefore, apply to the em-
ployment and misemplo3TOent of expressions. So it is necessar}^ to
recast what was said earlier. Statements about the misreading of
the logical powders of propositions and ideas should be reformulated
somewhat as follows.

Certain classes of expressions when functioning in certain classes
of contexts either have or are unthinkingly supposed to have a cer-
tain logical force. And when I speak of an expression as having or
teing credited with a certain logical force I mean no more than that
it expresses or is assumed to express an idea or proposition with
certain logical powers, in the sense adumbrated above. It is there-
fore always possible to inquire w'hat consequential propositions would
be true if the expression under investigation expressed or helped to
express a proposition the logical powers of which were analogous
to those of a known model. It is always initially possible that this
, logical experiment will reveal that some of the consequences of the
-assumption conflict with some of its other consequences and thus
leyeal that the attribution of this logical force to this expression in
&is use was a false one. The genuine logical force of the expression

Tptf. Function of the “Reductio ad Absurdum”

The discovery of the logical type to which a puzzle-generating
idea belongs is the discovery of the rales governing the valid argu-
ments in which propositions embodying that idea (or any other idea
of the same type) can enter as premises or conclusions. It is also
the discovery of the general reasons why specific fallacies result
from mis attributions of it to specific types. In general the former
discovery is only approached through the several stages of the latter.
The idea is (deliberately or blindly) hypothetically treated as homo-
geneous with one familiar model after another and its own logical
structure emerges from the consecutive elimination of supposed logi-
cal properties by the absurdities resulting from the supposals.

This program appears vexatiousiy circuitous and one is tempted
to dream of some direct way of fixing the logical powers of pu zz le-
generating ideas, w^hich shall share with the method of progressive
reductio the merit of being rigorous while improving on it by dis-
pensing with trial and error. But, whatever other methods of search
may be used, there remains this important fact about its object, that
to find or understand a rule it is necessar}^ to appreciate not only
what it enforces but also what it permits and what it forbids. People
are not fully seized of a logical rule if they have not considered the
absurdities against which it prescribes. The boundaries* of a right of
way are also boundaries of forbidden ground. So no method of dis-
covering the legitimate employments of a concept can dispense with
the method of forecasting the logical disasters consequent upon
illegitimate operations with it. Before the argument comes to its
close, it is necessar}^ to clear up three subsidiary points.

Systematic Ambiguity

It is commonly supposed that a particular concept is precisely
indicated by reference to a particular expression, as if for example
the idea of equality were unmistakably identified by being described
as that for which the word “equality” stands.

There are, of course, in all languages some words w^hich happen
to have twu or more different meanings. That is how puns are pos-
sible. But these ambiguities are of no theoretical interest. They are

[ 338 ] gilbert RYLE

(if it has a force at all) , must therefom be such that the propositions
which it helps to express have coi^titutions which are insured against
these and other contradictions.

^ ,, ■■■ [339 I

Arguments L J

LilS in ieir occurrence, they can be c™vented by simple
nr naraphrases and the different ideas expressed by a
^^m^on P P connection with one another that

^ ihich the word is used normally suffices to specify
Si.??Sis intended to be conveyed. But there is another sort of

of signification which characterizes the use not of a few
most or of ail expressions and which is such that the para-
Erases and translations of an expression with a certain elasticity of
will normally have a precisely similar elastiaty. This
i^^^biguity is systematic in further respects. The vanous ideas
■^^Lssed by an expression in its different uses are intimately con-
with each other. They are in one way or another different in-
flections of the same root.

'A dven word wUl, in different sorts of context, express ideas ot

an indSnite range of differing logical types and, therefore, with dif-
feient logical powers. xAnd what is true of single words is also true
of complex expressions and of grammatical constructions.

Consider the adjective ‘^punctual.’' It can be used to characterize
a person’s arrival at a place, the person who arrives there, his char-
acter, and even the average character of a class of persons. It would
be absurd to compare the punctuality of a man on a particular occa-
sion with that of his arrival on that occasion; it would be absurd to
compare the punctuality of his character with that of his arrival on
a particular occasion; and it would be absurd to compare the punc-
tuality of Naval officers as a class with that of a particular Na\al
officer. These and similar absurdities show that the word punctual
undergoes inflections of significance when applied to different types
of subjects. There would be the same inflections of significance in
French or German and parallel inflections with other words of the
same sort, like “tidy” and ‘'‘industrious.’ So, where precision is
wanted, it is wrong to speak of “toe idea’ of punctuality,^ although
the word “punctual” does not become a pun-word by having a dif-
-ferent logical force for each different ty^pe of context in which it is
. used.

A philosophically more interesting example is afforded by the
verb to ‘‘exist.” It may be true that there exists a cathedral in Ox-
ford, a three-engined bomber, and a square number between 9 and
^25, But the naive passage to the conclusion that there are three
;cxistents, a building, a brand of aircraft and a number soon leads
;? to trouble. The senses of “exists” in which the three subjects are said
exist are different and their logical behaviors are different. The
*-**-=^' of different logical inflections in the forces of expressions

[ 340 ] GILBERT RYLE

is made by the impact upon us of the absurdities resulting from
ignoring them; the determination of those difierences is done by
pressing the search for further such absurdities. Unnoticed systematic
ambiguities are a common source of type-confusions and philosophic,
problems. Philosophers are sometimes found lamenting this readiness
of languages to give to one expression the power of expressing an
indefinite variety of ideas; some of them even recommend reforms
of usage which will pin single meanings to single expressions. But,
in fact, the capacity of familiar dictions to acquire new^ inflections
of logical forces is one of the chief factors making original thought
possible. A new^ thought cannot find a new vehicle ready made for
it, nor can the discrimmation of the logical powers of new ideas
precede the birth of the knowledge (by w'ont) of how^ to think with
them. As some spanners are designed to be adjustable, so as to fit
bolts of the same shape but differeni sizes, so. though undesigned,
those linguistic instruments of thought are found to be most handy
which are the most readily adjustable. The suggestion that men
should coin a different diction to correspond with ever}' difference
in the logical powers of ideas assumes, absurdly, that they could be
aware of these differences before being taken aback by the para-
doxes arising from their naively attributed similarities. It is like sug-
gesting that Grill should precede the formation of habits or that chil-
dren should be tauahi the rules of gra m mar before learning to talk.

Abstractions

I have been spealdng so far as if ah ideas alike generate philo-
sophical puzzles. But this needs correction. To put it roughly, con-
crete ideas do not generate such puzzles, abstract ideas do. But this
disiinction between concrete and abstract as well as that between
lower and higher abstractions requires a clarification, of which no
more than a sketch can be given here. By a "concrete idea” is
meant one the original use of w^hich is to serve as an element in
propositions about what exists or occurs in the real world. It could
be introduced or explained to an inquirer by confronting him with
one or several specimens from the real world, or else by presenting
him with physical models, pictures or mental images of specimens.
Propositions containing such ideas can be called first-order propo-
sitions. Questions about their truth and falsehood can in favorable
cases be settled by observ'ation or sets of observations.

Ideas like spaniel, dog, ache, thunder in their originai use are
instances of concrete concepts. In this use they generate no philo-

Arguments

[341]

ouzzles, since one learns from the routines of dahy^exf^n-
P pe and the limits of their application. Their logical
.^^^ prShv’Ms taught by one’s daily walks. Such concepts are formed

- „nticin<^ similarities in the real world. , , t. . *

different from these are what are often called abstract
is a negative mark of these that a person cannot be mtro-
S to such concepts by being presented with correspondmg reali-
' ' ri^Nothing in the world exemphfies the economic man the

S'tMs idea occurs e.g. in the Spaniel is a descendant of the Wolf),

■ : ^ or 2 (as this occurs e.g. in 2 is a prime number). It is a positive

• mark of some abstract ideas that they can be expressed by abstract
nouns like “justice,” “circularity” and “wickedness”; but this is the

• exception rather than the rule. The proposition the economic man
' \ huvs in the cheapest and sells in the dearest market is an abstract

oroposition, though nothing in the vocabular}^ of the sentence indi-
cates that the proposition is of a different logical type Irom the ola
man buys his tobacco in the neighboring tobacconisfs shop.

Abstract propositions do not directly describe the real wond
but nor do they directly describe any other world. They apply mdi-
‘ - rectly to the real world, though there are various types of such indirect
; appHcation. Arithmetic is not about inventories, but inventones
satisfy arithmetical propositions; geometr\' does not describe Asia,
but the geography of Asia is an application of geometiy% and so on.
To form abstract ideas it is necessary to notice not similarities be-
tween things in nature but similarities between propositions about
tilings in nature or, later on, between propositions about propositions
about things in nature. . . . But this conclusion nas an air of mys-
tery, deriving from the fact that propositions are themselves abstrac-
tions. The world does not contain propositions. It contains people
believing, supposing and arguing propositions. This amounts (nearly
enough) to saying that the world contains linguistic and other ex-
pressions, used or usable by no-niatter-whom, which expressions,
when used, express truths or falsehoods. To talk about a given prop-
- osition is therefore to talk about what is expressed by any e?:pression

- (of no matter what linguistic structure) having the same logical

: ’ . force as some given expression, as such expressions are or might be

I h;;' intelligently used by persons (no matter whom).

^ , This doctrine that to speak of a specified proposition is to speak

of persons (no matter who) using expressions (no matter of what
% ' - sorts) having the same logical force as that of a given expression
can be proved. In any particular instance, it is always significant to
there is no such proposition, since the given sentence is

[ ] GILBERT RYLE

absurd, having, perhaps, parts which have correct uses in other con-
texts but cannot be combined in this way to form a sentence with an
integral logical force.

With these safeguards it is correct to say that some propositions
are about other propositions and are therefore second- or hinher-
order propositions. Some higher-order propositions, which form
perhaps, the most numerous class, are only about other propositions
in the special sense that they are about partial similarities between
otherwise different propositions. For any given proposition there
may be found a range of different propositions sharing with it and
with each other some one common factor. “Socrates is wise” ex-
presses a proposition having something in common with what is
expressed by “Plato sapiens est.’" This co mm on factor can be ex-
pressed by a skeleton sentence of the pattern “so and so is wise”
(where “so and so” announces the gap in the skeleton sentence).
Similarly the skeleton sentence “if p then expresses what is com-
mon to a range of hypothetical propositions.

Propositions about such factors of propositions, with certain
exceptions, are ordinarily said to be propositions about abstractions
or abstract ideas. They are higher-order propositions about isoiable
features of ranges of lower-order propositions and describe the loa-
cal force of skeleton sentences equipollent with a given skeleton
sentence. Thus, a proposition about wisdom does" not mention
Socrates or Plato; facts about Socrates and Plato are irrelevant to
its truth. Yet the general fact that there are or might be subjects
oi whom it could be true that they w’ere wise is not irrelevant to
the logical force of the word “wisdom” and it is consequently rele-
vant to the truth of propositions about wisdom. This illustrates the
sense in which it has been said that abstract propositions do not
describe the world, or zny other world, but do indirectly anoiv
to the world. It is always possible to accuse a submitted abstract
idea of absurdity or rather to accuse an, expression purporting to
express an abstract idea of being an absurd e.xpression. Naturally
enough language does not provide many nonsemical single word's
but there frequently occur absurd complex e.xpressions, purporting
to express complex concepts, when such a complex is illegitimated
The fact that such accusations are always significant proves that
abstract propositions always embody overt or covert inverted com-
mas. (Indeed any abstract proposition if expressed with maximum
logical candor would be seen to be describing a tenuous morsel of
the real world, namely an expression in inverted commas. But of
course it only mentions such an expression as a means of specif>'ing

Arguments [ 343 ]

or proix>sitioii wMctt is the logical force of that and any

■fboiripolcnt expression.) . j > ^ a a r

liere is, of course, an unliimted vanety of types and orders of
ideas, but all alike can generate philosophical puzzles, just
experience of the real world gives us no drill in their cor-
bel use. Mistaken views about abstractions are not rebutted by a
broised shin or a parched throat. Nor does the language used to
'express abstract ideas vary with their different varieties. The chart-
ing of their logical powers consists therefore in the checking of their
logical behavior against logical rules, which is the operation described
in tins lecture, i.e. the eiimmation by reductio ad absurdum of logical
powers incorrectly ascribed or ascribable to them.

Another general point can now be established. For any abstract
proposition there must be a range of propositions of a lower level,
since the abstract proposition describes factors common to them.
This implies that corresponding to any abstraction there is at a lower
proposition-level an idea being actually used (and not described).
There must bt at this lower level knowledge by wont of some
powers of this idea before there can begin the higher-level research
into the rules governing those powers. We must know in practice
how to decide whether Socrates is wise or clever before we can de-
bate the abstract question of the relations between wisdom and
cleverness. (Hence philosophy is sometimes said to tell us only
what we knew before. This is as true as the corresponding statement
about Mr. Jourdain’s knowledge of prose before his introduction to
grammar.)

This indicates what was missing in my prefatory account of the
method and effects of philosophical reasoning. This w’as likened to
' threshing, which separates the grain from the chaff, discards the
chaff and collects the grain. Philosophical reasoning separates the
genuine from the erroneously assumed logical powers of abstract
ideas by using the reductio ad absurdum argument as its fiail and
winnowing fan, but knowledge by wont of the use of concreter ideas
is also necessary as its floor.

Crucial and Cardinal Ideas

' Though all abstract ideas alike are liable to generate phiiosophi-
puzzles, some demand priority in philosophical examination. Of
. these one class consists largely of the new^ theory-shaping ideas which
“ are struck out from time to time in the fields of science, criticism,
- statesmanship, and philosophy by men of genius. Genius shows itself

[ ] GILBERT RYLE

not so much in the discovery of new answers as in the discovery of
new questions. It influences its age not by solving its problems "but
by opening its eyes to previously unconsidered problems. So the
new ideas released by genius are those which give a new direction
to inquiry, often amounting to a new method of thinking.

Such crucial ideas, being new, are at the start unco-ordinated with
the old.^ Their potency is quickly recognized but their logical powers
have still to be determined, as, correspondingly have those logical
powers of the old ideas w^hich have yet to be correlated with the
new. The task of assimilating the new crucial ideas into the un-
fevered blood-stream of workaday thought is rendered both more
urgent and more difiicult by the fact that these ideas necessarily besin
by being exciting. They shock the settled who execrate them as
superstition, and they spell-bind the young who consecrate them
into m3;th. That cloud and this rainbow are not dispelled until philos-
ophers settle the true logical perspectives of the ideas.

Quite distinct from these, though often integral to them, are what
may be described as philosophically cardinal ideas, those, namely,
the logical unravelling of which leads directly to the unravelling of
some^ complex tangle of interconnected ideas. Once these key-ideas
are charted, the geography of a whole region is, at least in outline,
nxed. No general clue can be given for predicting which ideas will
turn out to have this catalytic power. To discern this is the privilege
01 philosophic genius. ^

17

How I See Philosophy

BY FRIEDRICH WAISMANN

/ W3BAT PHILOSOPHY is?^ I don’t know, nor have I a set formula to
offer. Immediately I sit down to contemplate the question I am
ftooded with so many ideas, tumbling over one another, that I can-
not do justice to ail of them. I can merely make an attempt, a ver}^
inadequate one, to sketch with a few' strokes what the lie of the land
seems to me to be, tracing some lines of thought without entering
upon a close-knit argument.

It is, perhaps, easier to say w^hat philosophy is not than what it
is. The first thing, then, I should like to say is that philosophy, as it
is practised today, is unlike science; and this in three respects:
in philosophy there are no proofs; there are no theorems; and there
are no questions which can be decided, Yes or No. In saying that
there are no proofs I do not mean to say that there are no arguments.
Arguments certainly there are, and first-rate philosophers are recog-
nized by the originality of their arguments; only these do not work
in the sort of w'ay they do in mathematics or in the sciences.

^ There are many things beyond proof: the existence of material
objects, of other minds, indeed of the external world, the validity of
induction, and so on. Gone are the days when philosophers w'ere
trying to prove all sorts of things: that the soul is immortal, that this
. is the best of all possible worlds and the rest, or to refute, by “irre-
' futable” argument and with relish, materialism, positivism and what

Proof, refutation — these are dying words in philosophy (though
-'G. E. Moore stiU ‘‘proved” to a puzzled world that it exists. What

cs^y is r)|-_ Waismann’s contribution to Contemporary British Philosophy,

' dnn H. D. Lewis), copjo-ight 1956 by George Allen and Unwin Ltd,, Lon-

. . Witn whose kind permission it is here reprinted.

“ ^ ™ reply to a question put to me by the Editor (of Contemporary

[ 345 ]

[ 346 ] FRIEDRICH WAISMAI^

can one say to this — save, perhaps, that he is a great prover before
the Lord?).

But can it be proved that there are no proofs in philosophy? No;
for one thing, such a proof, if it were possible, would by its very
existence establish what it was meant to confute. But why suppose
the philosopher to have an I.Q. so low as to be unable to learn from
the past? Just as the constant failure of attempts at constructing a
perpetual motion has in the end led to something positive in physics,
so the efforts to construct a philosophical “system,” going on for
centuries and going out of fashion fairly recently, tell their tale.
This, I think, is part of the reason why philosophers today are get-
ing weaned from casting their ideas into deductive moulds, in the
grand style of Spinoza.

\%at I want to show' in this article is that it is quite wrong to
look at philosophy as though it had for its aim to provide theorems
but had lamentably failed to do so. The w^hole conception changes
when one comes to realize that w'hat philosophers are concerned
with is something difierent — neither discovering new propositions nor
refuting false ones nor checking and re-checking them as scientists
do. For one thing, proofs require premisses. Whenever such prem-
isses have been set up in the past, even tentatively, the discussion at
once challenged them and shifted to a deeper level. Where there are
no proofs there are no theorems either. (To write down lists of
propositions “proved” by Plato or Kant: a pastime strong!}- to be
recommended.) Yet the failure to establish a sort of Euclidean
system of philosophy based on some suitable “axioms” is, I submit,
neither a mere accident nor a scandal but deeply founded in the
nature of philosophy.

Yet there are questions; (and arguments). Indeed, a philosopher
is a man who senses as it were hidden crevices in the build of our
concepts where others only see the smooth path of conimonplaceness
before them.

Questions but no answers? Decidedly odd. The oddness may
lessen when w^e take a look at them at closer range. Consider two
famous examples: Achilles and the tortoise, and the astonishment of
St. Augustine when confronted with the fact of memoiy^ He is
amazed, not at some striking feat of memory, but at there being
such a thing as memory at all. A sense-impression, say a smell or a
taste, floats before us and disappears. One moment it is here and
the next it is gone. But in the galleries of the memoiy^ pale copies
of it are stored up after its death. From there I can drag them out
when and as often as I wish, like, and yet strangely unlike, the

j

See Fhilosophy [ 347 ]

in that they are not perishable like the momentary
what was transitory has been arrested and has achieved
' But who can say how this change comes about?
v.- 4 :v*-^'^^Herc^the veiy fact of memory feels mystifying in a way in which
asMng for information do not; and of course it
is' mt a factual question. What is it?

: -From Plato to Schopenhauer philosophers are agreed that the
-■• 'mmcQ-ol their philosophizing is wonder, ’^hiat gives rise to it is
recondite and rare but precisely those things which stare us
memory, motion, generi ideas. (Plato: What does
*‘horse’* mean? A single particular horse? No, for it may refer to
my horse; all the horses, the total class? No, for we may speak of
this or that horse. But if it means neither a single horse nor all horses,
what does it mean?) The idealist is shaken in just the same way
when he comes to reflect that he has, in Schopenhauer’s words, ‘"no
knowledge of the sun but only of an eye that sees a sun, and no
knowledge of the earth but only of a hand that feels an earth.” Can
it be, then, that nothing whatever is knowm to us except our own
consciousness?

In looking at such questions, it seems as if the mind’s eye were
growing dim and as if everything, even that which ought to be abso-
lutely clear, was becoming oddly puzzling and unlike its usual self.
To bring out what seems to be peculiar to these questions one might
say that they are not so much questions as tokens of a profound
uneasiness of mind. Tr\^ for a moment to put yourself into the frame
of mind of which Augusdne was possessed when he asked: How is
it possible to measure time? Time consists of past, present and future.
The past can’t be measured, it is gone; the future can’t be measured,
it is not yet here; and the present can’t be measured, it has no ex-
tension. Augustine kIlev^■ of course how time is measured and this
was not his concern, \\hat puzzled him was how it is possible to
measure time, seeing that the past hour cannot be lifted out and
placed alongside the present hour for comparison. Or look at it this
way: what is measured is in the past, the measuring in the present:
how can that be?

The philosopher as he ponders over some such problem has the
..appearance of a man who is deeply disquieted. He seems to be strain-
nig to grasp something which is beyond his powers. The words in
. such a question presents itself do not quite bring out into the
...open the real point — ^which may, perhaps more aptly, be described
the recoil from the incomprehensible. If, on a straight railway
. 'journey, you suddenly come in sight of the very station you have

'

'rrm

[ 348 ] FBIEDRICH WAISMANK

just left behind, there will be terror, accompanied perhaps by slight
giddiness. That is exactly how the philosopher feels when he says to
himself, “Of course time can be measured; but how can it?” It is as
though, up to now, he had been passing heedlessly over the diffi-
culties, and now, all of a sudden, he notices them and asks himself
in alarm, “But how can that be?” That is a sort of question which
we only ask when it is the very facts themselves which confound us,
when something about them strikes us as preposterous.

Kant, I fancy, must have felt something of the sort when he sud-
denly found the existence of geometry a puzzle. Here we have prop-
ositions as clear and transparent as one would wish, prior, it seems,
to ail experience; at the same time they apply miraculously to the
real world. How is that possible? Can the mind, unaided by experi-
ence, in some dark manner actually fathom the properties of real
things? Looked upon in this way, geometry takes on a disturbing air.

We all have our moments when something quite ordinary^ sud-
denly strikes us as queer — ^for instance, when time appears to us as
a curious thing. Not that we are often in this frame of mind: but on
some occasions, when we look at things in a certain way, unex-
pectedly they seem to change as though by magic: they stare at us
with a puzzling expression, and we begin to wonder whether they
can possibly be the things we have known all our lives.

“Time flows” we say — a natural and innocent expression, and
yet one pregnant with danger. It flows “equably,” in J^ewton’s phrase,
at an even rate. What can this mean? When something moves, it
moves with a definite speed (and speed means: rate of change in
time). To ask with what speed time moves, i.e. to ask how quickly
time changes in time, is to ask the unaskable. It also flows, again
in Newton’s phrase, “without relation to anything external.” How
are we to figure that? Does time flow on irrespective of what happens
in the world? Would it flow* on even if everything in heaven and on
earth came to a sudden standstill as Schopenhauer believed? For if
this w'ere not so, he said, time would have to stop with the stopping
of the clock and move with the clock’s movement. How' odd: time
flow^s at the same rate and yet without speed; and perhaps even with-
out anything to occur in it? The expression is puzzling in another
way. “I can never catch myself being in the past or in the future,”
someone might say; “whenever I think or perceive or breathe the
word ‘now,’ I am in the present; therefore I am always in the
present.” In saying this, he may think of the present moment as a
bridge as it were from which he is looking down at the “river of
time.” Time is gliding along underneath the bridge, but the “now”

FMlosophy

[349 ]

take part in the motion. What was future passes into the
'Lj rrjr nt' fis just below the bridge) and then into the past, while the

‘f tiie “self’ or the “I,” is always in the present. “Time flows
the ‘now/ ” he may feel to be a quite expressive metaphor,
it' sbuncis all right — until he suddenly comes to his senses and,
a start, realizes, “But surely the moment files?” (Query: How

,i,^ l 0 -$iicceed in wasting time? Answer: In this way, for instance — ^by

'With eyes closed or staring vacantly in front of oneself, to
the present moment as it is Sitting by.) He may come now to
at matters in a different way. He sees himself advancing through
*i towards the future, and with this goes a suggestion of being
/ ' active^ Just as at other times he may see himself floating down the
"fe'^eam whether he likes it or not. “'^ai exactly is it that is moving
events in time or the present moment?” he may wonder. In
' the first case, it looks to him as if time were mo\4ng while he stands
; still; in the second case as if he were moving through time. “How
exactly is it,” he may say in a dubious voice, “am I always in the

■ present? Is the present always eluding me?” Both ring true in a way;
tsut they contradict each other. Again, does ii make sense to ask,

' ^At what time is the present moment?” Yes. no doubt; but how
can it, if the “now” is but the fixed point from which the dating
: of any event ultimately receives its sense?

So he is pulled to and fro: “I am always in the present, yet it
slips through my fingers; I am going for^'ard in time — no, I am
carried down the stream.” He is using different pictures, each in its
way quite appropriate to the accasion; yet when be tries to apply
them jointly they clash. “Wffiat a queer thing time must be,” he may
; say to himself with a puzzled look on his face, "’what after all is time?”

■ — expecting, half-expecting perhaps, that the answer will reveal to
him time’s hidden essence. Ranged beyond the inteliecmal are deeper

-- levels of uneasiness — terror of the ineviiabilin’ of lime's passage, with
- all the reflections upon life that this forces upon us. Now all these
I anxious doubts release themselves in the question. “What is time?”

, (En passant this is a hint that one answer will never do — will never
remove all these doubts that break out afresh on different levels and
y-"yet'are expressed in the same form of words.)
r As we all know what time is and yet cannot say what it is it
; : feels^ mystifying; and precisely because of its elusiveness it catches
our imagination. The more we look at it the more we are puzzled:
charged with paradoxes. “What is time? W^at is this being
op of movement only without anything that is moving?”

How funny to have it bottled up! “Tve got here

It may be well at this point to remind ourselves that the words
^'question” and '‘answer/’ “problem” and “solution” are not always
used in their most trite sense. It is quite obvious that we often have
to do something very^ different to find the way out of a difficulty. A
problem of politics is solved by adopting a certain line of action,
the problems of novelists perhaps by the invention of devices for
presenting the inmost thoughts and feelings of their characters; there
is the painter’s problem of how to suggest depth or movement on
the canvas, the stylistic problem of expressing things not yet cur-
rent, not yet turned into cliche; there are a thousand questions of
technology which are answered, not by the discovery of some truth,
but by a practical achievement; and there is of course the “social

[ 350 ] FRIEDRICH WAISMAKH

in my hand the most potent, the most enigmatic, the most fleeting
of all essences — ^Time.” (Logan Pearsall Smith of an hour-glass.)
For Shelley it is an “unfathomable sea! whose waves are years,” a
“shoreless flood,” for Proust — ^weE, why not leave something to the
reader?

But isn’t the answer to this that what mystifies us lies in the
noun form “the time”? Having a notion embodied in the form of a
noun almost irresistibly makes us turn round to look for what it is
“the name of.” We are trying to catch the shadows cast by the
opacities of speech. A wrong analogy absorbed into the forms of
our language produces mental discomfort; (and the feeling of dis-
comfort, wffien it refers to language, is a profound one). “AH sounds,
all colors . . . evoke indefinite and yet precise emotions, or, as I
prefer to think, call down among us certain disembodied powers
whose footsteps over our hearts we call emotions” (W. B. Yeats).

Yet the answer is a prosaic one: don’t ask what time is but how
the word “time” is being used. Easier said than done; for if the
philosopher rectifies the use of language, ordinary^ language has “the
advantage of being in possession of declensions,” to speak with
Lichienberg, and thus renews its spell over him, luring him on into
the shadow^ chase. It is perhaps only when we turn to languages of
a widely different grammatical structure that the way towards such
possibilities of interpretation is entirely barred- “It is^ highly probable
that philosophers within the domain of the Ural-Altaic langcages
(where the subject-concept is least developed) will look differently
‘into the world’ and be found on paths of thought different from
those of the Indo-Europeans or Mussulmans” (Nietzsche).

1 See FMlosaphy [ 351 J

In pMosophy, the real problem is not to find the answer
question but to find a sense for it.

.-' To ^ “solution’^ of such a “problem” consists let

’ll ^ait' with Achilles who, according to Zeno, is to this day chasing
f"-'''’" V"' tie" tortoise. Suppose that Achilles runs twice as fast as the tor-
't^se. If the tortoise’s start is 1, Achilles will have to cover suc-
c^ssively 1, . . . ; this series is endless: so he can never

’ catch the tortoise. “Nonsense!” (a mathematician’s voice), “the
ytm of the infinite series is finite, namely 2, and that settles it.”
Though perfectly true, his remark is not to the point. It does not
• ■ ■ remove tiie sting from the puzzle, the disconcerting idea, namely,

that however far we go in the series there is always a next term, that
the lead the tortoise has in the race, though naturally getting smaller
and smaller, yet never ceases to be: there can be no moment when
It is strictly zero. It is this feature of the case, I suggest, that we do
not understand and which throws us into a state of confusion.

I But look at it this way. Suppose that we apply the same sort of
argument to a minute, then we shall have to argue in some such way
as this. Before the minute can be over the first half of it must elapse,
then one-quarter of it, then one-eighth of it, and so on ad infinitum.
This being an endless process, the minute can never come to an end.
Immediately we have the argument in this form, the blunder leaps
to the eye: we have been confusing two senses of “never,” a temporal
and a non-temporal one. While it is quite correct to say that the se-
quence 1, ^4, Vs, . . . never ends, this sense of the word “never”

has nothing whatever to do with time. .All it means is that there is
no last term in the series, or (what comes to the same} that to any
term, no matter how^ far out in the sequence, a successor can be
constructed according to the simple rale “halve it”: that is meant
here by “never”; whereas in saying, for instance, that man will never
find out anything to avert death, “never” is meant in the sense “at
no time.” It is clear that the mathematical assenion concerning the
■ possibility of going on in the sequence by forming new terms according
'• - . ^ the rule does not state anything about actual occurrences in time.

... ^e mistake should really be obvious: in saying that, since the start
r-r.- n getting progressively smaller and yet can never cease to be,
Aclffles can never catch the tortoise, we jump from the mathe-
wn-temporal to the temporal sense. Had there been two dif-
words in our language to mark these senses the confusion could
arisen, and the world would be poorer for one of its
tr attractive paradoxes. But the same w^ord is as a matter of course

lased with different meanings. Result: something like a conjuring

I Philosophy , [ 353 }

in fa¥or of a three-valiied logic with ‘‘possible” as a
/ 'diird tmth-valiie alongside “true” and “false.”)

f ■ " ^ The way out is clear enough. The asker of the question has fallen

I • Mo the error of so many philosophers: of giving an answer before
. stopping to consider the question. For is he clear what he is asking?
I- ' He to suppose that a statement referring to an event in the
I*' ' r „ future is at present undecided, neither true nor false, but that when

I' ' the event happens the proposition enters into a sort of new state,

f- ■ that of being true. But how are we to figure the change from “un-

f ' / ■ dedded” to “true”? Is it sudden or gradual? At what moment does
i - the statement “it will rain tomorrow” begin to be true? When the

f , ’ first drop falls to the groimd? And supposing that it will not rain,

%- when will the statement begin to be false? Just at the end of the day,

1: a 12 p.m. sharp? Supposing that the event has happened, that the

r statement is true, will it remain so for ever? If so, in what way?

- Does it remain uninterruptedly true, at evory moment of day and
night? Even if there were no one about to give it any thought? Or
is it true only at the moments when it is being thought of? In that

I case, how long does it remain true? For the duration of the thought?

|v We wouldn’t know how to answer these questions; this is due not

I to any particular ignorance or stupiditj^ on our part but to the fact

that something has gone wrong with the way the words “true” and
I “false” are applied here.

I If I say, “It is true that I was in America,” I am saying that I

was in America and no more. That in uttering the words “It is true
Ir that — ” I take responsibility upon myself is a different matter that

I does not concern the present argument. The point is that in making

|: a statement prefaced by the words “It is true that” I do not add any-

I thing to the factual information I give you. Saying that something

f. is true is not making it true: cp. the criminal lying in court, yet every

I time he is teUing a lie protesting, Ms hand on his heart, that he is

] telling the truth.

- What is characteristic of the use of the words “true” and “false”

1i and what the pleader of logical determinism has failed to notice is
this. “It is true” and “it is false,” while they certainly have the force
■ ' of asserting and denying, are not descriptive. Suppose that someone

says, “It is true that the sun will rise tomorrow” all it means is that
. ’ ^ sun will rise tomorrow: he is not regaling us with an extra-

C;;:. V of the tmeness of what he says. But supposing that he

'L V. y- ^ instead, “It is true now that the sun win rise tomorrow,”
would boil down to something like “The sun will rise tomorrow

n

[ 354 ] FRIEDRICH WMSMANN

now”; which is nonsense. To ask, as the puzzle-poser does, “Is it
true or false now that such-and-snch will happen in the future?’’
is not the sort of question to which an answer can be given: which
is the answer.

This sheds light on what has, rather solemnly, been termed the
“timeiessness of truth.” It lies in this that the clause “it is true
that — ” does not allow of inserting a date. To say of a proposition
like “Diamond is pure carbon” that it is true on Christmas Eve
would be just as poor a joke as to say that it is true in Paris and not
in Timbuctoo. (This does not mean that we cannot say in certain
circumstances, “Yes, it was true in those days” as this can clearly
be paraphrased without using the word “true.”)

Now it begins to look a bit less paradoxical to say that when a
philosopher w'ants to dispose of a question the one thing he must
not do is: to give an answer. A philosophic question is not solved: it
<d/-ssolves. And in what does the “dissolving” consist? In making the
meaning of the w^ords used in putting the question so clear to our-
selves that we are released from the spell it casts on us. Confusion
was removed by calling to mind the use of language or, so far as
the use can be distilled into rules, the rules: it therefore a con-
fusion about the use of language, or a confusion about rules. It is
here that philosophy and grammar meet.

There is one further point that needs elucidation. Wnen we say
of a given assertion, e.g. “It is raining,” that it is true we can hardly
escape the impression that we say something “about” the assertion,
namely, that it has the property of trueness. To make such a state-
ment seems, then, to say more than what was asserted origmaliy,
namely, that it is raining and that this assertion is true. That, how-
ever, leads to queer consequences. For in v/hich sense does it say
more? Consider first under w'hich circumstances it would be appro-
priate to say of tw^o given propositions that the one says “more”
than the other. “This is red” says more than “this is colored” for
the obvious reason that anyone can conclude from the first statement
to the second but no one reversely; similarly “today is Tuesday”
says more than “today is a weekday.” The criterion, then, suggests
itself that, given two propositions p and q, p says more than q, ii
^p. q is meaningful and p, ^q contradictory. The holder of the
view that “p is true” says more than p {p standing e.g. for “It is
raining”), may now be challenged to explain what he means by
that. Is he using the word “more” in the sense just explained? If so,
the curious consequence ensues that it must make sense to assert

[ 355 ]

that is in our case, “It is not true that it is
it is raining.” Since this obviously is not what he had
what does he mean? We are not contradicting him; we
him of how these words have always been used by
lion-philosophical contexts that is, and then point out that,
stiQ wants to use them in this sense, to say what he wanted to
lands him in an absurdity. All we do is to make Mm aware
his own practice. We abstain from any assertion. It is for Mm to
what he means. Not that he cannot do it. In ascribing truth
a ^ven statement, he might say, he wants to express perhaps
cither (i) that it is “in accordance with fact” or sometMng of the
sort; or (ii) that he knows that it is true. In the first case he is faced
the same dilemma, namely, that it must make sense to say,
"It is not in accordance with the facts that it is raining and it is
raining”; in the second fresh diMculties are breaking out. For one
thing, the words “it is true that — v/hen uttered by different people,
then mean different things; for another, and this is more fatal
to the advocate of fatalism, in construing the words in this sense,
he cuts the ground from under Ms own feet. No one would then be
worried by the question whether, supposing that it is false now^
that he will write a certain letter tomorrow, it follows that it will
really be impossible for him to write that letter, that this line of
conduct is barred to him, logically barred. For since “it is false
sow” means in the new^ sense “he doesn't know yet” nothing follows
and the whole question evaporates.

My reason for going into this tangle at some length is that the
method applied in unravelling it presents some interesting features.
First, we don’t jorce our interlocutor. We leave him free to choose,
accept or reject any w^ay of using his words. He may depart from
ordinaiy usage — language is not untouchable — if it is only in this
way that he can explain himself. He may even use an expression
one time in tMs, another time in that, way. The only thing we insist
upon is that he should be aware of what he is doing. If w^e strictly
adhere to tMs method — going over the argument, asidng him at each
tep whether he is willing to use an expression in a certain w^ay, if
offering Mm alternatives, but leaving the decisions to Mm and
pointing out what their consequences are — no dispute can arise.

arise only if certain steps in tMs procedure are omitted so
t looks as if we had made an assertion, adding to the world’s
a new apple of discord. This would be the true way of doing
undogmatically. The diMculty of this method lies in

[ 356 ] FMEDRICH WAISMANK

presenting the subject in a manner which can easily be taken in

in arranging the cases and the ways in which they are connected
through intermediate links so that we can gain a clear synoptic view
of the whole.

Second, we do not use arguments in order to prove or disprove
any “philosophic view.” As we have no views we can afford to look
at things as they are.

Next, we only describe; we do not “explain.” An explanation,
in the sense of a deductive proof, cannot satisfy us because it pushes
the question “Why just these rules and no other ones?” only one
stage back. In following that method, we do not want to give rea-
sons. AH we do is to describe a use or tabulate rules. In doing this,
we are not making any discoveries: there is nothing to be discovered
in grammar. Grammar is autonomous and not dictated by reality. Giv-
ing reasons, bound as it is to come to an end and leading to something
which cannot further be explained, ought not to satisfy us. In gram-
mar we never ask the question “why?”

But isn’t the result of this that philosophy itself “dissolves’’?
Philosophy eliminates those questions which can be eliminated by
such a treatment. Not all. of them, though: the metaphysician’s crav-
ing that a ray of light may fall on the mystery of the existence of this
w’orld, or on the incomprehensible fact that it is comprehensible,
or on the “meaning of life” — even if such questions could be shown
to lack a clear meaning or to be devoid of meaning altogether, they
are not silenced. It does nothing to lessen the dismay they rouse in
us. Tiiere is something cheap in “debunking” them. The heart’s
unrest is not to be stilled by logic. Yet philosophy is not dissolved.
It derives its weight, its grandeur, from the significance of the ques-
tions it destroys. It overthrow's idols, and it is the importance of these
idols which gives philosophy its importance.

Now^ it can perhaps be seen why the search for answers fitting
the moulds of the questions fails, is bound to fail. They are not real
questions asking for information but “muddles felt as problems”
(Wittgenstein) which wither aw^ay w^hen the ground is cleared. If
philosophy advances, it is not by adding new propositions to its list,
but rather by transforming the whole intellectual scene and, as a
consequence of this, by reducing the number of questions w^hich
befog and bedevil us. Philosophy so construed is one of the great
liberating forces. Its task is, in the words of Frege, “to free the
spirit from the tyranny of words by exposing the delusions which
arise, almost inevitably, through the use of a word language.”

m'-t'See Fhilosaphy

[357 ]

.-j* ’ ' ■ Wbat, only criticism and no meat? The philosopher a fog dispeller?
^ lij^i all he was capable of I would be sorry for him and leave
his devices. Fortunately, this is not so. For one thing, a
^" 'pfiiosopMc question, if pursued far enough, may lead to something
' ‘ ^^live— for instance, to a more profound understanding of language.

. ^ke the sceptical doubts as to material objects, other minds, etc.

tfe first reaction is perhaps to say: these doubts are idle. Ordinarily,

~ when I doubt whether I shall ^sh this article, after a time my
- ifoubt comes to an end. I cannot go on doubting for ever. It’s the
destiny of doubt to die. But the doubts raised by the sceptic never
cSe. Are they doubts? Are they pseudo-questions? They appear so
onl}’' when judged by the twin standards of common sense and
common speech. The real trouble lies deeper: it arises from the
sceptic casting doubt on the very facts which underlie the use of
language, those permanent features of experience which make con-
cept formation possible, which in fact are precipitated in the use of
om most common words. Suppose that you see an object in front
of you quite clearly, say, a pipe, and when you are going to pick it
up it melts into thin air, then you may feel, ‘‘Lord, I’m going mad”
or something of the sort (unless the whole situation is such that you
have reason to suspect that it was some clever trick). But w^hat, the
sceptic may press now, if such experiences were quite frequent?
Would you be prepared to df^olve the connection between different
sense experiences which form the hard core of our idea of a solid
object, to undo what language has done — ^to part with the category
of thing-hood? And would you then be living in a phenomenalist’s
paradise with color patches and the other paraphernalia of the sense-
datum theory, in a disobjected, desubstantialized world? To say in
such circumstances, “Lx)ok, it’s just tabling now” would be a joke
(for even in the weakened verb forms “tabling,” “chairing” an
element of the thing-category lingers on). That is why the sceptic
... Struggles to express himself in a language which is not fit for this
■ purpose. He expresses himself misleadingly when he says that he
such-and-such facts: his doubts cut so deep that they affect the
. fehnc of language itself. For what he doubts is already embodied in the
speech, e,g. in what is condensed in the use of thing-
J^ouient he tries to penetrate those deep-sunken layers, he
/ ■ language in which he ventilates his qualms — ^with the

ifeh

Iff; : ■■

[ 358 ] FMEDHICH WAISMaNH

result that he seems to be talking nonsense. He is not. But in order'
to make his doubts fully expressible, language would first have to
go into the melting-pot. (We can get a glimmering of what is needed
from modem science where all the long-established categories—,
tfainghood, causality, position — ^had to be revolutionized. This re-
quired nothing less than the construction of some new language, not
the expression of new facts with the old one.)

If we look at the matter in this way the attitude of the sceptic
is seen in a new light. He considers possibilities which lie far outside
the domain of our current experience. If his doubts are taken seriously,
they turn into observations which cast a new and searching light
on the subsoil of language, showing what possibilities are open to
our thought (though not to ordinan^ language), and what paths
might have been pursued if the texture of our experience were
different from w’hat it is. These problems are not spurious: they
make us av/are of the vast background in which any current experi-
ences are embedded, and to which language has adapted itself; thus
they bring out the unmeasured sum of experience stored up in the
use of our words and syntactical forms.

For another thing, a question may decide to go in for another
career than dissolving: it may pass into science. Frege, for instance,
was prompted to his inquiries by philosophical motives, namely,
to find a definite answer to the question about the nature of arith-
metical truths — ^whether they are analnic or s>mthetic, a priori or
a posteriori. Starting from this question and pursuing it with all
possible rigor, he was led to unearth a whole mine of problems of a
scientific nature; and proceeding along these lines, he came to fashion
a new' instrument, a logic, which in delicacy and range and power
far surpassed anything that went by this name before, a subject
revealing to this day new and unexpected depths. True, the question
from which Frege set out was not too clearly defined owing to the
imprecise nature of the Kantian terms in which it was expressed.

A w^hoie chapter might be written on the fate of questions, their
curious adventures and transformations — how they change into
others and in the process remain, and yet do not remain, the same.
The original question may split and multiply almost like a character
in a dream play. To mention just a few examples: can logic be
characterized completely in a formal way, i.e. without bringing in
any extraneous ideas such as the use of language and all that goes
with it? Can arithmetic be characterized in any such way, entirely
“from within”? Or will any interpretation include some Erdenrest
of the empiric? These questions have given rise to extensive research

Wgm ? Fhihsopky [ 359 ]

mathematical interpretation of formal systems. The query how
lo^ca! intuition is correct has got ramified into a bunch of ques-
pertaining to the theory of logical types, the axiom of choice,
“indeed to a far more fundamental issue, namely, whether
i^dhiaiy logic itself is ‘"right” as contrasted with the system of
fcfOTSces evolved by the intuitionists. Or again, are there undecid-
'* questions in mathematics, not in the restricted sense of G5del,

''-'lull imdecidable in an absolute sense? Are there natural limits to
’ S'" generalization? It is interesting to watch how from a question of this

not too precise, somewhat blurred, new and better defined
>{; detach themselves, the parent question — ^in Frege’s case

. S l^nlosophic par excellence — giving rise to a scientist’s progeny.

- • ’ Now something else must be noted — ^how^ these questions become,
not only precise, but clear (which is not the same thing). To illustrate,
can the infinity represented by ail natural numbers be compared with
the infinity represented by all points in space? That is, can the one
be said to be less than, or equal to, the other? When it was first asked,
the question had no clear sense — ^perhaps no sense at all. Yet it
^ gmdfii G. Cantor in his ingenious search. Before set theory was
discovered — or should I rather say “invented”? — ^the question acted
as a sort of signpost pointing vaguely to some so far uncharted
' - region of thought. It is perhaps best characterized by saying that it

guides our imagination in a given direction, stimulates research
along new lines. Such questions do not “dissolve” : they are solved,
only not in the existing system of thought but rather by constructing
a new conceptual system — such as set theory — ^where the intended
and faintly anticipated sense finds its full realization. Tliey are there-
• foie of the nature of incitements to the building of such systems, they

point from the not-yet-meaningful to the meaningful.

The question is the first groping step of the mind in its joumeyings
. - : &at lead towards new horizons. The genius of the philosopher shows
; . itself nowhere more strikingly than in the new kind of question he

bmgs into the world. Wliat distinguishes him and gives him his
- ; : place is the passion of questioning. That his questions are at times

• , not so clear is perhaps of not so much moment as one makes of it.

is nothing like clear thinking to protect one from making dis-
It is ail very well to talk of clarity, but when it becomes an
it is liable to nip the living thought in the bud. This, I am
^ deplorable results of Logical Positivism, not

^ founders, but only too striking in some of its followers.
at these people, gripped by a clarity neurosis, haunted by fear,
tongue-tied, asking themselves continually, “Oh dear, now does this

1

make perfectly good sense?” Imagine the pioneers of science, Kepler
Newton, the discoverers of non-Enclidean geometry, of field physics*
the unconscious, matter waves or heaven knows what imagine thein
asking themselves this question at every step — ^this would have been
the surest means of sapping any creative power. No great discoverer
has acted in accordance with the motto, “Everything that can be said
can be said clearly.” And some of the greatest discoveries have even
emerged from a sort of primordial fog. (Something to be said for
the fog. For my part, Tve always suspected that clarity is the last
refuge of those who have nothing to say.)

The great mind is the great questioner. An example in point is
Kant’s problem “How is geometiy^ possible?” The way to its solution
was only opened up through the rise of the “axiomatic method.”
Seeing that the axioms of geometrv' are capable of an indefinite
number of different interpretations and that the particular way they
may be interpreted is irrelevant to deductive purposes, Hilbert
separated what belongs to the logical fomi of the Axioms from what
belongs to their intuitional (or other) content and turned the whole
question by saying: a point, a straight line, etc., may be anything
that satisfies the axioms. As the business of deduction hinges only
on the relations in which the basic terms stand to each otfaer^and not
on the “content” we associate with them, and as these relations are
fully set out in the axioms, the axioms in their totality^ determine
what a “point,” a “line,” etc., is so far as it is sufficient for deductive
needs. TTirough the rise of this technique it became an parent that the
word “geometry’,” as understood by Kant, covers, in fact, two totally
different sciences, mathematical and physical geometry’. It was the
failure to distinguish between them that produced KanVs perplexity.
“So far as the laws of mathematics refer to reality’, they are not
certain; and so far as they are certain, they do no: refer to reality”
(Einstein). Kant’s credit lies in having seen that there is a problem,
not in having solved it.

But here a new problem presents itself; How do vve know what
will satisfy a given question? More genei'ally: How does the answer
St the question? Questions of the current sort (“What is the right
time?”) show already by their form wffiat sort of aiis\ver to expect.
They are, so to speak, cheques with a blank to be filled; yet not
always so: Augustine’s question, “How is it possible to measure
time?” or Kant’s question, “How is geometry possible?” do not trace
out the form of the answer. There is no obvious hnk between ques-
tion and answer, any more than there is in the case of asking “What
is a point?” When Hilbert’s idea — ^that the axioms of geometiy

f&^-fSee PMlosopny ^ l — j

-^vide the “implicit definition” of the basic terms — ^was
^Irowunded it came totally unexpected; no one had ever thou^t
tefore; on the contrary, many people had an tmeasy feehng
■ if this were a way of evading the issue rather than an answer,
. ^longst them no less a man than Frege. He thought the problem

^^^is^^ere anything one can do to make a man like Frep see
that the axiomatic method provides the correct answer? Can it, for
e^ple be proved to him? The point to which attention must now
be dmvm, though it should really be obvious, is that such a proof
taomot be' riven, and it cannot because he, the asker, has &st to be
tnmed round to see the matter differently. What is required is a
change of the entire way of thinking. Indeed, anyone who is pu2zled
by this problem and yet refuses to accept Hilbert’s solution only
betrays &at he has got stuck in the groove hollowed out by the form
in which the question is put. “A point is — ” he begins and then stops.
What is to be done to help him to get out of the groove or,^ better
still, to make him shift for himself when he feels “cramped” in it,
is a discussion, not a proof.

Fre^e behaves not so very unlike a man mystified by the question,
“What Is time?” We may suggest converting the latter into the
question how the word “time” “is being used (which would bring
him down to earth) . But aren’t we cheating him? We seem to be
holding out the answ'er to one question, but not to that one which
he was asking. He may suspect that we are tiy^ing to fob him oS with
the second best we have in'store, his original question still remaining
an enigma. Similarly Frege; he considered it a scandal thai. the
questions “What is a point?” “What is a number?” were still un-
answered.

In either of these cases, the aim of a discussion, in the absence
of a proof, can only be to change the asker’s attitude. We may, for
instance, scrutinize similar, or partially similar, cases, point out that
the form of the answer is not always that of the question; by going
patiently over such cases, the vast background oi analogies against
.which the question is seen wHl slowly change. The turning up oi a

■ Wide field of language loosens the position of certain standards
.'r’lriiich are so ingrained that we do not see them for what they are;
.and if we do this in an effective manner, a mind like Frege s wili be
released from the obsession of seeking strainingly for an answer to

■ fit the mould. Arguments are used in such a discussion, not as proofs
;;ti 30 ugh but rather as means to make him see things he had not
jjsfoticed before; e.g. to dispel wrong analogies, to stress similarities

[ ] FEIEDBJCH WAISMaNH

with Other cases and in this way to bring about something like a
shift of perspective. However, there is no way of proving him wrong
or bullying him into mental acceptance of the proposal; when all is
said and done the decision is Ms.

But here more is at stake than loosening a cramped position-—.
it is a question of escaping the domination of linguistic forms. How
often are we merely following the channels carved out by numberless
repetition of the same modes of expression — as when we say, un-
suspectingly, “lime flows” and are, when confronted (say) with
Augustine’s paradox, suddenly shocked out of complacency. Exist-
ing language, by offering us only certain sterot}^d moulds of ex-
pression, creates habits of thought wMch it is almost impossible to
break. Such a mould is, e.g. the actor-action scheme of the Indo-
European languages. How deep their influence is can perhaps be
surmised from Descartes’ conclusion from thinking to the presence
of an agent, an ego, different from the thinking, that does the think-
ing — a conclusion so natural and convincing to us because it is
supported by the whole weight of language. Frege's obsession with
the question “What is a number?” is another case. As we can speak
of *'the number five,” five, Frege argued, must be the proper name of
an entity, a sort of Platonic crystal, indicated by means of the definite
article. (A Chinese pupil of mine once informed me that Frege’s
question is unaskable in Chinese, “five” being used there only as a
numeral in contexts like “five friends,” five boats,” etc.). Again,
when w^e say of a given statement that it is true, we seem to be saying
sometMng “about” it — evidence of the power of the subject-predicate
cliche. Indeed, so strong is the temptation to construe it in this w’ay,
namely, as a statement about a statement, that the idea of a different
interpretation scarcely occurs to us. It is imponant to notice that in
doing so we assimilate the expression to analogical forms; but it is
no less important to notice that none of these analogies needs to be
present to our minds: it is enough if they make themselves felt in a
dim, inarticuiated way. Such patterns have an effect on us lilte thou-
sands of explicit analogies: they act upon us, one might say, like a
field of force, a language field, that draws our mental gaze in a
certain direction. And, I venture to add, it is precisely because of
of the fleeting, half-formed, shadow-like nature of these analogies
that it is almost impossible to escape their influence. If we are taken
in by them, it is our fault. A philosopher, instead of preachina the

f^^%m^fSeePi^sophy [ _ 1

.;'_^ swimnier must be able to swim up-stream, so the philos^
master the imspeakabiy difficult art of thinking up-speech,

another point. When we dissuade a man like Frep

search, we seem to be hmderiiig him from reaching &e
get out to reach. Does our discussion clash, then, with his
®^eh? And, if so, in which way? First of all, in no clearly definable
for he is not yet clearly aware what he is aiming at, and the
“‘i -'Sssion brings him gradually to see things in a different light. How
change brought about? WeU, he first saw the question m
^om with other ones, and these analogies are, one by one, de-
or rather, in the course of the discussion they are seen to
' - L Reading. In proportion as the whole conceptual background

^ changes he comes to see that something is wrong with the way he
puts his question, that the attainment of his object is no longer
^tisfying. It is not that he gives up because he has tried very hard,
but in vain, and has now got tired: no, he gives up because he
**sees” the question differently. And in what does this consist? Well
ffl the fact that he is now well aware of the analogies which were
’misleading him, that he sees the question against a different linguistic
background (a ‘‘figure” sometimes changes when it is seen against
a different “ground”), that a certain strain disappears and that he
says, with a sigh of relief, “Yes, that’s it.”

The philosopher contemplates things through the prism ot
language and, misled (say) by some analogy, suddenly sees thing*
In a new strange light. We can cope with these problems only by
di^ng dovvm to the" soil from which they spring. What we do is to
fight up the mental background from which the question has de-
tached itself; in a clearer perception of some of the crucial concepts
the question transforms itself into another one. Not that it has been
answered in the current sense. Rather we have removed the factors
that prompted the question by a more profound and penetrating
analysis. The essence of this process is that it leads the questioner
on to some new aspect — and leads him with his spontaneous consent.

■ :Hb agrees to be thus led and therefore ends by abandoning his
- search. We caimot constrain anyone who is unwilling to follow the
' mvr direction of a question; we can only extend the field of vision
of the asker, loosen his prejudices, guide his gaze in a new direction:
c . ; / . . tet ail this can be achieved only with his consent.

our critical analysis we try to counteract the influence of
t ; ...the language field, or (what comes to the same) we may help the

1 :.:

[ 3^ ] FRIEDRICH WAlSUmn

questioner to gain a deeper insight into the nature of what he is
seeking first of all — ^make him see the build of the concepts and
the moulds in which he expresses the question. VlTiat matters is
more like changing his outlook than proving to him some theorem;
or more like increasing his insight. Insight cannot be lodged in a
theorem, and this is the deeper reason why the deductive method is
doomed to fail; insight cannot be demonstrated by proof.

What it comes to in the end is that the asker of the question, in
the course of the discussion, has to make a number of decisions.
And this makes the philosophical procedure so unlike a logical
one. He compares, for instance, the case before him with analogous
ones and has to judge how far these analogies hold. That is, it is for
him to decide how far he is willing to accept these analogies: he has
not, like a slave, to follow blindly in their track.

Science is rich in questions of this type. They are not scientific
questions properly and yet they exercise scientists, they are philo-
sophic questions and yet they do not exercise philosophers.

WTiat I have wanted to say in this section and have not said,
or only half-said:

(1) Philosophy is not only criticism of language: so construed,
its aim is too na^^ow^ It is criticizing, dissolving and stepping over all
prejudices, loosening all rigid and constricting^moulds of thought,
no matter whether they have their origin in language or somewhere
else.

(2) What is essential in philosophy is the breaking through to a
deeper insight — ^which is something positive — ^not merely the dis-
sipation of fog and the exposure of spurious problems.

(3) Insight cannot be lodged in a theorem, and it can therefore
not be demonstrated.

(4) Philosophic arguments are, none of them, logically com-
pelling: they really screen what actually happens — the quiet and
patient undermining of categories over the whole field of thought.

(5) Their purpose is to open our eyes, to bring us to see things
in a new way — ^from a wider standpoint unobstructed by misunder-
standings.

(6) The essential difference between philosophy and logic is that
logic constrains us while philosophy leaves us free: in a philosophic
discussion we are led, step by step, to change our angle of vision,
e.g. to pass from one way of putting a question to another, and this
with our spontaneous agreement — a thing profoundly different from
deducing theorems from a given set of premises. Misquoting Cantor
one might say: the essence of philosophy lies in its freedom..

5ec FhUosophy

[365 ]

■?-

IV

'^ere is a notion that philosophy is an exercise of the intellect
&^"that philosophic questions can be settled by argument, and con-
" ^ knew how to set about it. What seems to me

however, is that I cannot find any really good hard argument;
' l^iBore that, the example just discussed must make it doubt-
'fid whether any compelling argument can be found. Out of this
I incline to come to a new and somewhat shocking conclusion:

- mat the thing cannot be done. No philosopher has ever proved any-
The whole claim is spurious. What I have to say is simply
Ihis. Philosophic arguments are not deductive; therefore they are
Slot rigorous; and therefore they don’t prove anything. Yet they
have force.

Before going into the matter, I want to show, quite summarily
first, how unpiausible the view is that rigorous arguments are applied
in philosophy. A first alarming sign can perhaps already be seen in
the notorious fact that the ablest minds disagree, that what is indis-
putable to the one seems to have no force in the eyes of the other.
In a clear system of thought such differences are impossible. That
they exist in philosophy is Vr'eighty evidence that the arguments have
none of the logical rigor they have in mathematics and the exact
sciences.

Next, arguments, in the way they are thought of, must contain
inferences, and inferences must start somewhere. Now where is the
philosopher to look for his premises? To science? Then he will ‘"do”
science, not philosophy. To statements of everyday life? To particular
ones? Then he will never be able to advance a single step beyond
them. To general statements? If so, a number of questions raise
their ugly heads. By what right does he pass from “some” to “all”?
(“To Generalize is to be an Idiot,” W, Blake.} Can he be sure that
his premises are stated with such clarity and precision that not
a ghost of a doubt can creep in? Can he be sure that they contain
aieat, are not anal3d;ic, vacuous, definitions in disguise and the like?
Can he be sure that they are true? (How can he?) And even sup-
posing, what is not the case, that all these requirements could be
TOt, there is still another task looming before him when it comes
-to /developing the consequences: can he be sure how to operate with
^ terms? (How can he?) I am not letting out a secret when I say
that the ordinary rules of logic often break down in natural speech —
a fact usually hushed up by logic books. Indeed, the words of com-

[ 366 ] FRIEDRICH WAISMANK

mon language are so elastic that anyone can stretch their seme to fit
Ms own whims; and with tMs their “logic” is queered. (Plenty of
scope for a “natural logic”; we know that we are unhappy; so we
are unhappy. We know that we are unhappy; so we are great, Pascal.
“If she had perished, she had perished:” does this entail that she has
not perished? If so, by what rule? “If I believed that I should be very
silly indeed:” does this, or does tMs not, entail that I don’t believe
it? Natural language holds logical problems of its own, lots of them.)

This brings me to another point Ordinary language simply has
not got the “hardness,” the logical hardness, to cut axioms in it. It
needs something like a metallic substance to carve a deductive system
out of it such as Euclid’s. But common speech? If you begin to draw
inferences it soon begins to go “soft” and fluffs up somew^here. You
may just as w^ell carve cameos on a cheese souffle. (My point is:
language is plastic, yielding to the will to express, even at the price
of some obscurity. Indeed, how' could it ever express anytMng that
does not conform to the cliche? If logicians had their way, language
would become as dear and transparent as glass, but also as brittle
as glass: and what would be the good of making an axe of glass that
breaks the moment you use it?) But language is not hard. And that
is why it is dangerous in pMlosophy to hunt for premises instead of
just going over the ground, standing back and saying: look.

Most pbilosopmc arguments, to ignore constructions a la Spinoza,
hinge on such points as what “can” and what “cannot” be said or
what sort of question it is “proper” and what sort of question it
would be “inappropriate” to ask. Much skill and ingenuity' has been
spent in elucidating such questions as to whether a certain metaphor
is “natural,” a certain diction “fitting.” It would not be right to
burke the point that considerations such as these, w'hile apparently
pertaining to matters of style, contribute in fact largely to the force-
fulness of an argument, indeed play a very real and decisive part in
the way they make us look at the subject. In going over, examining
and comparing the various modes of expression that center around
certain key notions, for instance, “imagination,” “memory,” “pleas-
ure,” we catch the first glimpse of what is sometimes called the
“logic” of these notions. Now can any of these things be proved?
Can it be proved, for example, that a certain diction is “fitting”?
(Remember, no such thing as a definition of a “well-formed form-
ula.”) No philosopher has ever made so much as an attempt. Every-
one uses words in this way and he leaves it at that; and rightly so.
For what sort of reasons could he give anyway? Here already, at the
very threshold, the idea of a philosopMc proof begins to ring hollow.

See Fhilosophy [ 367 ]

, bnt the ordinary use of language.” x4]l right; but even so,

'4 "is i»t that one ‘‘cannot” use language differently. To illustrate:

music” — does this “teff” you amthing? Perhaps not; yet a
Whig hke ‘‘Architecture is frozen music” (Goethe) drives the point
^Whe- To say “The arms are full of blunted memories” sounds odd,
J iiatil you come upon it in Proust’s context. The “will to under-
stand” does not even flinch before those bogies of the logician,
contradictions: it transforms them, wresting a new sense from the
' apparent nonsense. (“Dark with excess of light,” “the luminous
'^oom of Plato” — ^just to remind the reader of two examples of
0>hndgc.) There are about 303 reasons wby we sometimes express
ourselves in a contradiction, and understandably so.

Result; it cannot even be proved that a given expression is natural,
a metaphor fitting, a question proper (or unaskable), a collocation
of words expressive (or devoid of meaning). Nothing of the sort
can be demonstrated.

Two other points reinforce what has been said. What we some-
times do in a philosophical discussion is not argue at all but simply
raise lots of questions — a method brilliantly employed by Ryle.
Indeed, a volley of perplexing questions can certainly not be de-
scribed as an argument and a foriiori not as a logical one, yet it is
no less effective in making one rum back in recoil to consider one’s
views. Lastly, though on the surface the philosopher seems to be
engaged in much the same thing as a logician is, for instance, in
testing an argument for any loose links in it or in building up an
argument, this should not mislead us. For if he were to construct
rigorous proofs, where are the theorems established by them? What
has he to show as the fruit of his labors?

I have not raised any of these questions w^antonly; they force
themselves on eveiy^one who tries to arrive at a clear and unbiased
view of the matter. Should these difficulties not have their origin
in the nature of philosophy itself?

V

I proceed now to consider philosophic arguments, especially
those which are regarded as constituting a decisive advance, to see
. whether they give us any reason for modiri’ing the view^ advocated
here. There are only a few^ classical cases. One of them is Hume’s
- p^i^hrated argument to show^ that the relation of cause and effect is
ptnnsically different from that of ground and consequence. Now
does this “proof’ consist? He reminds us of what we have

[ 368 ] FRIEDRICH WAISMANK

always known: that, while it is self-contradictow to assert the grotiacj
and deny the consequence, no such contradiction arises in assuming
that a certain event, the ‘‘cause,” may be followed not by its usual
effect but by some other event. Ji it is asked “Is this a proof?” what
is one to say? It certainly is not the sort of proof to be found hx
a deductive system. Much the same applies to Berkeley’s argument
when he tells us that, try as he might, he cannot call up in his mind
an abstract idea of a triangle, of just a triangle with no particular
shape, any more than he can conceive the idea of a man without
qualities. Is this a proof? He points out the obvious. (Only it wants
a genius to see it.)

To take my own argument against logical fatalism, it is not strict
The decisive step consists in follov/ing a certain analogy with other
cases. It is analogical, not logical. Similarly the argument used
against Zeno is not conclusive. (I have no space to enlarge upon that.)

Now^ for tW'O more examples, one of the current sort of argument
applied today by philosophers, the other taken from Aristotle.

When we say of someone that he “sees” or “hears” an aeroplane,
or “descries,” “detects” a lark in the sty, or again that he “tastes”
or “smells” roast pork, w^e do not ascribe to him an activity. That
“seeing” is not a sort of doing can be illustrated, e.g. by calling at-
tention to the fact that we don’t use the continuous present tense.
We say “I see the clock,” not “I am seeing the clock” (save G. E.
Moore, who, oddly enough, regularly says that he “is seeing his right
hand”), whereas it is perfectly correct to say “I am looking at the
clock, listening to its ticking,” and so in the other cases. Again,
while it is proper to say “I have forgotten to post the letter,” no
one would say “I have forgotten to see the letter-box.” There is
no sense in asking you, when you look at me, whether your seeing
is easy or difficult, quick or slowish, careful or heedless, whether you
see me deliberately and whether you have nov/ finished seeing me.
So, it is argued, perceiving is not a doing (an argument used by
myself in lectures).

The point to be labored is that this argument is not conclusive.
Odd as it sounds, “I have finished seeing you” may be said, though
only in very special circumstances. A man with impaired eyesight
who, unable to take in the shape as a whole, has perhaps to scan
the face bit by bit in search of some characteristic marks might say,
and understandably, “Now I have finished seeing you.” We too are
occasionally in a not much better position, as when, in magnesium
light, we look at some scene, and ^erwards complain, “Too quick,
I couldn’t take it in.” It would seem then that there is no more

• i See Philosophy *■

■ o difference in degree between this case and the normal ones.
S L2f Srtainiy; bS what would you think of a mathematician
.^^^rems cSapse when apphed to shghtly out-of-the-way

^fr mv next example I choose pleasure. Aristotle, in critici^g
Plato pointed out that if pleasure were a process gomg on m to
f^d enjoy something swiftly or slowly— an ardent which is
Almost a tombshen in its destructive power. Certainly,^ to speak in
«:nch terms is very odd and sounds absurd. Yet, if I stram my imagi-
TlTTcl perhaps bring myself to conceive of a set of cncum-
under which it would not be entirely unnatural to say such
^ T., Uctf-nino- tn muslc. for exampie, when I am foUowmg a

to be dinereni irum wiiat x — ^ w *

mncir Th** very quality of my eniovment seems to cnange as it
SShiS’of S sL and geni or df the ndd. imoricating flow o
rimsio had entered into it. If I say, in the one ease, tnat I was
enjoying it leisurely like basking m the sun or sipping wine, in the
other that I was suddenly carried away, breatnlessly loUowmg ite
onrush and enjoying it like a storm at sea— ^oes tins sound hi^e sheer
nonsense? So there does seem to be a time mctor m pleasure.

Amongst the most pow^erful weapons in the philosopher s ry
are reductio ad absurdum and inhnite regress arguments Before
proceeding to an appraisal of these forms oi reasomng, it wiU be
wen to consider how they work in their home iand_^mathema m .

Let me choose as a typical case the proof that \' 2 is irration .
If it were a rational number, we could nnd two integers m and n
. such that

t i j

even, m must be even; hence

m- = 2n-

We may then argue as follow's. rt'.- is
m = 2mi. Substitution yields

I - 2m-r = n-.

As is even, n must be even; hence n = 2ni. Substitution yields
I mi" = 2ni-.

K, then, two integers m and « exist which stand in the relation (1),
■thev must have halves which stand in exactly the same relauon (,

• W these must have halves which stand in the same relation ana
:so on ad infinitum; which is plainly impossible, m and n bem|&mte.
- ^erefore the tentative assumption (1) cannot hold, and V-

[ 370 ]

FRIEDRICH WAISMANN

not be rational. Q.E.D. This is the prototype of a refutation by
infinite regress.

Arguments of this type have been applied outside mathematics.
However, when I come to look at them a bit more closely I begin
to hesitate. An example will illustrate my doubts. An argument pro-
pounded against the use of mechanical models is this. If the elastic
properties of matter can be explained as being due to electric
forces with which the molecules act on each other, it surely is point*
less to explain the action of the electric forces as being due to the
elastic properties of a mechanical medium, the “ether.” To do this
is to go round in a circle: elasticity is explained in terms of electric
force, and electric force in terms of elasticity; while the attempt to
break out of the circle by supposing that the elasticity of the ether
is due to “electric forces” acting between the ether particles and
these to the elastic properties of a second-order ether is to be pushed
into an infinite series of reduction steps. Thus the mechanistic pro-
gram is faced with a dilemma both horns of which are equally faial.

A formidable argument — or is it? I can well imagine an un-
daunted champion of the lost cause retort: “Not a bit of a regress.
Yes, the ether is elastic, not, however, in the sense in which a spring
is: while eiasticiU* of matter can be reduced to electric force, elasticity
of the ether, being an ultimate postulate of the theor}% cannot be
reduced any further.” And. with this the argument falls to the ground.

But this is unconvincing, it will be said. 1 agree; I am not such
an imbecile as to plead for retaining mechanical models and the
rest. My point is only to see whether this “refutation” is compelRng.
It isn't. The advocate of models is not forcibly dislodged from his
position. There is, it would seem, always a way of getting out of
the dilemma — of wriggling out if you like — which foils the argument.
What is shown in it is merely that to cling ic models of this sort
becomes, in the circumstances, vei}' unnatural. But to say that some-
thing is unnatural is not to say that it is logically impossible: yet
this is what the argument should establish. In the mathematical proof
cited above no loophole was left for wriggling out. The whole de-
duction was a “chain of adamant” — ^precisely the sort of thing the
argument under review is not.

Consider now a similar argument. There cannot be any such thing
as volitions, it has been said. Volitions were called in by theorists
to provide causes not only for what we (intentionally) do but also
for mental processes or operations such as controlling an impulse,
paying heed to something, and the like. As a consequence of this,
acts of will were supposed to be the sort of thing the presence of

Philosophy

[ 371 ]

makes an action “voluntary,” or wiiich — somehow, in some

( ■''f lC'' way — “gets itself translated” into a bodily or mental

' ' ' ' act In volitions were thought of as causes as well as effects of
'■ii ':’ other, mental or physical, occurrences. Now the dilemma: if my
[ •;.l . jjjjliing of the trigger were the result of a mental act of “willing to

' pSiAe trigger,” what of this mental act itself? Was it willed or un-
■ ' ^ed? If unwilled, it cannot be called voluntary and therefore not
a volition; if willed, then we must suppose, according to the theory',
that it results from a prior act, namely, “vvilling to will to pull the
fi/'-' v:. trigger,” and that from another ad infinitum, leaving no possibility
! ' . fot me ever to start.

■' BrilEaiit as the argument is, the point to be brought up here is
I?/ ’ -. v- -only whether it is logically fatal. Does it really prove that the as-
sumption of acts of willing involves an innnite regress? A believer in
such acts need not be cowed into submission. To ask of volitions
whether they are themselves voiuntaiy’ or involuntaiy^ acts, he may
' say, is plain nonsense. Only an aciion can be voluntan” or invol-
untary, not an act of will. It is just the poin: that an act of will is
• - an act of will and does not issue from any anterior act of will, any
more than, in order to recall a thing I mus: first recall w^hat I warn:
to recall, and before I can even do that I must recall that I want to
recall w^hat I want to recall, and so on innnhum. Just as I can

recall a thing without need to call in an act of recalling what I want
to recall, so my pulling the trigger may be the direct result of an
act of vail without the latter issuing from a parent act of will. Thus
the whole argument apparently crumbles awa}'.

This is meant not to belittle the argument or detract from its
. force, but only to get clear as to what sor: of force it has. If it were
conclusive, it would, with its destructive power, do away with a good
many more acts and states of mind, no: only with volitions — with
intending and desiring, for instance. Indeed, precisely similar argu-
ments can be constructed ‘‘to deal wirh them.'’ Intention: though
clearly not the sort of thing to be classed as a simple ''act.*’ ii yet
: ^ somehow to “connect” with what goes on in us before we

ij y: .• cany it into action — such as considering, planning, hesitating, choos-
^ let US say, intend to find a naw in a given argument,

i;,. and when I subsequently turn it over in my mind, this will be the

I '7. ; • of my intention. Some mental operations, then, can arise from

^ ^mtention, they are “intended.” So what of the intention itself?

intended or unintended? If the intention is not intended, it is
intention, and if it is intended it must be due to another in-
f and this to yet another ad iniiniium. Similarly in the case

n

^ FRIEDRICH WAISMaKN

of desire. Suppose that I feel a desire for a certain thing, is this
desire itself desired or undesired? Either answer lands us in ab-
surdities.

If the strength of the argument were to lie in its structure it
wo^d, with its devastating effect, apply after the exchange of some
of Its terms for other ones, e.g. “volition” for “intention”— provided
of course, that certain other circumstances essential to the reasoning
are the same. Yet, whOe the first argument sounds, to say the least
very plausible, no one will be duped by its caricatures. So if it has
any force it cannot owe it to its structure and consequently cannot
be of a logical sort. It is meant to refute the existence of a kind of
mental thrust; but then w'e should remember that to prove the non-
existence of something is alwaj/s a precarious business. “No one has
ever proved the non-existence of Apollo or Aphrodite” it has
observed; too much weight, then, need perhaps not be laid on this
particular case. What is disturbing, hovrever, is the ease with which
arguments can be cast into pseudo-deductive moulds. And it is
this fact to which I wish to call attention by examining the argu-
ment. As has been shown in the preceding discussion, it is not'^an
isolated case. No philosophic argument ends with a Q.E.D. How-
never forces. There is no bullying in philosophy,
neither with the stick of logic nor with the stick of "language.

VI

In throwing such strong doubts on the power of arguments as
used by philosophers I may seem to deny them any value what-
ever. But such is not my intention. Even if they are lacking in logical
iigOi this certai^y has not prevented an original thinker from using
tnem successfully, or from bringing out something not seen before
or not seen so clearly. So in the case I have discussed: something
IS seen m_ that argument, something is made dear, though perhaps
not quite m the sense intended by the arguer. If so, something very
important has been left out from the picture.

Perhaps our objections have been doing injustice to philosophic
arguments. They were, quite mistakenly as I hope to have shown,
supposed to be proofs and refutations in a strict sense. But what
tte phfiosopher does is something else. He builds up a case. First,
e makes you see all the weaknesses, disadvantages, shortcomings
ot a position; he brings to light inconsistencies in it or points out
how unnatural some of the ideas underlying the whole theorv' are
y pushing them to their farthest consequences; and this he "does

- I See Fhllosaphy [ ]

^tii the stroBgest weapons in his arsenal, reduction to absurdity
'-and infinite regress. On the other hand, he offers you a new way
of looting at things not exposed to those objections. In other words,
to submits to you, like a barrister, all the facts of his case, and
you axe in the position of the judge. Yon look at them carefully, go
Into the details, weigh the pros and cons and arrive at a verdict.
But in arriving at a verdict you are not following a deductive high-
way, any more than a judge in the High Court does. Coming to a
decision, though a rational process, is very" unlike drawing conclu-
sions from given premises, just as it is very unlike doing sums. A
judge has to judge, we say, implying that he has to use discernment
m contrast to applying, machine-like, a set of mechanical rules.
There are no computing machines for doing the judge's work nor
could there be an}' — a trivial yet significant fact. When the judge
reaches a decision this may be, and in fact often is, a rational re-
sult, yet not one obtained by deduction; it does not simply follow
from such-and-such: what is required is insight, judgment. Now’ in
arriving at a verdict, you are like a judge in this that you are not
carrying out a number of formal logical steps: you have to use dis-
cernment, e.g. to descr}^ the pivotal point. Considerations such as
these make us see what is already apparent in the use of ‘Tational,”
that this term has a wider range of application than what can be
established deductively. To say that an argument can be rational
and yet not deductive is not a sort of contradiction as it would in-
evitably be in the opposite case, namely, of saying that a deductive
argument need not be rational.

This alters the whole picture. The point to be emphasized is that
a philosopher may see an important truth and yet be unable to
demonstrate it by formal proof. But the fact that his arguments are
no! logical does nothing to detract from their rationally\ Tc return
to our; previous example, the argument used against volition, though
.it is not what it professes to be, logically destructive, nevertheless
bss a force difficult to resist. Now’ to what is this due? It does not
need much acumen to find the answer. It is the whole arrangement
of so many felicitous examples, preceding the argument, and their
masterly analysis, which breathes life into its bare bones; aided
by the fact that the connection between a mental thrust and
bocMy movement is allowed to remain a myster}^ The unsatis-
^oriness of this position, together with the amassing of hosts of
-Unanswerable questions and very striking examples — ^this makes the
.^tgament so convincing.

What do you find in reading Ryle or Wittgenstein? Lots of ex-

f ^ . FRIEDRICH WAISMAHN

amples with little or no logical bone in between. Why so manv e
^ples? They speak for themselves; they usuaUy are more transpareS
man the trouble maker; each one acts as an analog: too-ether tK«
light up the whole linguistic background with the effect that th
case before us is seen in the light they produce. Indeed, exampks
aptly arranged are often more convincing and, above aU, of a moS
^tmg efif^t than an argument which is anyhow spidery. Not that
fee proofs proffered are valueless: a reductio ad absurdum alw^s
pomts to a toot m thought, and so does an infinite resress But
they point only. The real strength lies in the examples. AU {he proofs
m a good book on philosophy, could be dispensed with, without
losmg a whit of its convmcingness. To seek, in phUosophy, for rig-
orous proofs IS to seek for the shadow of one’s voice. ^ ^ ^

In order to forestaU misinterpretations which wiU otherwise cer-
aimy anse I have to concede one point: arguments on a small scale
contaimng a few logical steps only, may be rigorous. The^Ss'l^ce
of iny remarks IS that the conception of a whole phUosophical view
-from Herachtus to Nietzsche or Bradley-is never a matter
logical steps. A Weltanschauung like any of these or even a new ap-
proach Idee that of Wittgenstein is never “arrived at,” in piScZ

hv ^ ^“luted

' logical reasomng: though arguments mav plav a patt in

mal^g them acceptable. But some authors have disdained eve^fhaT
itte one remainmg question to be asked is this- if the nhUos-

aS -y p« how has h”™

leTd^f ^ road is

in^. This leads to a new and deeper problem.

VII

H “ philosophy?” and to replv, “To

dt • -oil, honoVkere

^ due, i suppress what I was going to say; except perhaps this.

^ u -li ®°methmg deeply exciting about philosophyf a fLt not
mte^gible on such a negative account. It is not a mker of ‘-clanfy-

S the^^LeZh^ i“g»rage” nor of any oth«

them?, ^ Philosophy is many things and

n ?ne ^ ^ ^ -^re asked to express

essential feature I would^ un-
na?e?^- pWiosophy worth the

shape Wherr^r?*^ ^^^es its visible

shape. When I say vision” I mean it: I do not want to romanticize.

J Philosophy [ 375 ]

is characteristic of philosophy is the piercing of that dead
cciist of tradition and convention, the breaking of those fetters which
bind ns to inherited preconceptions, so as to attain a new and broader
looking at things. It has always been felt that philosophy
slionid reveal to ns what is hidden. (I am not quite insensitive to
Ibe ^ view.) Yet from Plato to Moore and Witt-

genstein every great philosopher was led by a sense of vision: without
1 so one could have given a new direction to human thought or
opened windows into the not-yet-seen. Though he may be a good
technician, he will not leave his marks on the histor}^ of ideas. What
is decisive is a new way of seeing and, what goes with it, the will to
transform the whole intellectual scene. This is the real thing and
ever^^thing else is subservient to it.

Suppose that a man revolts against accepted opinion, that he
feels ‘'cramped” in its categories; a time may come when he believes,
rightly or wrongly, that he has freed himself of these notions; when
he has that sense of sudden growth in looking back at the prejudices
which held him captive; or a time when he believes, rightiy or
wrongly, that he has reached a vantage point from which things can
be seen to be arranged in clear and orderly patterns while dijfficulties
of long standing dissolve as though by magic. If he is of a philosophic
cast of mind he w'ill argue this out with himself and then, perhaps,
to impart what has dawned on him to others. The arguments he
wiE offer, the attacks he will make, the suggestions he will advance
are all devised for one end: to win other people over to his own
way of looking at things, to change the whole climate of opinion.
Though to an outsider he appears to advance all sorts of arguments,
this is not the decisive point. What is decisive is that he has seen
things from a new angle of vision. Compared to that everything else
is secondary. Arguments come only afterwards to lend support to
what he has seen. “Big words, not eveiy^ philosopher, etc.:” bui
wbere should one get one’s bearings if not from the masters? And
besides, once tradition has given way there is always ample scope
for specialists to reduce some “pockets of resistance.” Unpalatable
though it may be, behind the arguments so weli-planned, so neat and
logical, something else is at work, a win to transform the entire way
of thinking. In arguing for his viewy the philosopher will, almost
against his will, have to undermine current categories and cliches of
thinkmg by exposing the fallacies which underly the established
Ttews he is attacking; and not only this, he may go so far as to
^stion the canons of satisfactoriness themselves. In this sense,
philosophy is the re-testing of the standards. In every philosopher

t 1 FRIEDRICH WAISMANN

lives something of the reformer. That is the reason why any advance
in science when it touches the standards is felt to be of philosophic
significance, from Galileo to Einstein and Heisenberg.

If there is any truth in this, the relation of logic and philosophy
appears in a new light. What is at issue is not a confiict between a
formal and a less formal or informal logic, nor between the behavior
of techmcal and eveiy'day concepts, but something radically differ-
ent. It is the difference between drawing a conclusion and seeincr
or making one see, a new aspect.

To put the matter in a nutshell, a philosophic argument does
more and does less than a logical one: less in that it never estab-
lishes anything conclusively; more in that, if successful, it is not
content to establish just one isolated point of truth, but effects a
change in our whole mental outlook so that, as a result of that,
myriads of such little points are brought into view or turned ou:' of
sight, as the case may be. Are iOustrations necessary'? Once Hume
had exposed the_ fallacies of his predecessors when dealing with the
notion of causality he had made it impossible for anyone to think
along the lines of Spinoza whose world looks to us sltrange as the
moon. Suppose that you look at a picture-puzzle: at first you can
see in it only a maze of lines; then, suddenly, you recognize a human
met. Can you now, having discovered the face, see the lines as
before? Clearly not. As with the maze of lines,, so with the muddle
ciea.red up by^Kume: to recapture the mood of the past, tc travel
back into the fog has become impossible — one of the big difficulties
of understanding history-’ of philosophy. It is for the same reason that
the nse of the linguistic technique in our day has put an end to the
great speculative systems of the past.

A philosophy is an attempt to unfreeze habits of thinking, to
replace them by less stiff and restricting ones. Of course, these "may
in time themselves harden, with the result that they effig progress':
Kant, the Alleszermalmer to his contemporaries, yet proudly up-
holding his table or categories — which appear to us unduly' narrow.
The Uberaior of yesterday may turn into the tyrant of tomorrow.

It can now be seen that the philosopher is not doing what the
lo^cian does only less competently but doing something altogether
aifferent. A philosophic argument is not an approximation of a logi-
cal one nor is the latter the ideal the philosopher is striving for. Such
^ account totaUy misdescribes what really takes place. Philosophy
is not an exercise in formal logic, philosophic arguments are not
chains of logical inference, only bungled ones, nor can they by any
effort be recast into deductive moulds. What is being confused here

Philosophy [ 377 ]

scieBtist’s aim to find new truths and the philosopher’s aim
■■'Ib insight. As the two things are so entirely out of scale it is
wonder that the philosopher cannot move in the logician’s
Not even if the logician himself is fighting the battle. The
’-dash over the law of excluded middle in mathematics is a clash
between two parties, each in possession of clear and precisely defined
"'concepts. Yet there seems to be no way of settling the dispute fay
cogcBt argument. If it were true that phiiosopfaical troubles arise
fiom the loose nature of our everyday concepts, why should such
conflicts break out in the exactest of the sciences?

There have never been any absolutely cogent reasons for parting
with the law of excluded middle, accepting Darwinism, giving up
the Ptolemaic system or renouncing the principle of causality. If any
of these things could be demonstrated how does it come that there
are always partisans of the “lost causes”? Are they like the unluck}^

‘ drcie-squarers, v/asting their time in trying to do what has been
shown to be logically impossible? The truth is that conflicts of this
type cannot be resolved, not entirely, either by adducing factual evi-
dence or by logical demonstration. Both sides, of course, bring up
arguments in the combat but they are not decisive. These are battles
never lost and never won irrevocably. It is a typical situation, a recur-
rent theme in the histor}- of human thought.

\^flienever science arrives at a crucial, stage w^here the funda-
mental notions become imceriain and are held as it were in solution,
disputes of an odd land are breaking out. The mere fact that lead-
ing scientists, in spite of dinerences in temperament, outlook, etc.,
take part in them, feel bound to do so, should make us reflect.
Now what the protagonists avowedly or unavowedly are trying to
do is to win their fellow scientists over to their own way of think-
ing; and to the degree to which their arguments are attempts at
changing the whole intellectual attitude they take on a philosophical
character. Is this coincidence?

I have so far spoken of “seeing a new aspect” without making
sn attempt to explain the term. I hope now^ to do so, though only
. .perfunctorily, by giving one or two illustrations. There is a sort of
connected with the idea of certain discoveries. Descartes,
i.-fcrinstance, was the discoverer of analytic geometr}^ But could he

looking for it sounds down-
absurd. What we are inclined to say in such a case is: to seek

J 378 ] FRIEDRICH WAISMANN

for analytic geometiy is not possible — ^first because it was not seen
and then because it was seen. But if he could not seek, how could
he find? This leads us straight to the heart of the matter.

Consider first an entirely imaginaiy case. In the propositional
calculus, as it was built up by Frege, two primitive ideas occur,
“not” and “or.” It was later discovered by Sheffer that the whole
calculus can be based on one single idea (his “stroke” function).
Of what kind was this discovery? Suppose that Frege, by a curious
chance, had written aU his logical axioms in the form

-( )v-( )

i.e. as a sum of two negations, but had none the less mistakenly
believed that two symbols were required for expressing these laws,
namely and “v.” Imagine nov/ that someone else looking at
these formulae is struck by what, on our assumption, has escaped
Frege, namely that they all have one and the same structure and
require therefore only one symbol. In what exactly does his dis-
covery consist? In his seeing the formulae in a new way, in his
reading a new structure into them. What matters is his apprehension:
so long as he does not see the structure of a new system in the old
one he has not got it. Anyone may look at the formulae and yet not
perceive what SheSer has perceived, the occurrence of an identical
structure. This is the discovery’, not the introducing of a special
symbol for a combination of the old ones. It w^ould have been quite
enough, for instance, had Sheffer merely pointed out the constant
recurrence of this structure in all the laws without providing his
“stroke”; that is inessential.

This example may illustrate what is meant by the “seeing of a
new aspect.” Seeing such an aspect is often the core of a new dis-
cover}’. If you look at the formulae, the moment you notice the new
structure in them they suddenly seem to change — a phenomenon
akin to seeing a figure, say, a drawm cube differently, now as solid
and protruding, how as hollow and receding. The one pattern sud-
denly “jumps” into the other. Similarly in our case, though there
are also difierences; thus the new aspect, once it has dawned, can
steadily be held in mind and has not that perceptual instability. The
apprehension of a new^ pattern in the formulae seems to hold in it
actually more of a visual experience, anyhow to be more closely
akin to it than it might at first appear. Seeing and interpreting,
looking and thinking seem as it were to fuse here.

If it is now asked whether it is possible for anyone to seek for

'-Bm I Fhihsophy [ 379 ]

sew aspect, what is one to reply? Well, that something can be
jjx a new way is seen only when it is seen in this way. That an
g^pect is possible is seen only when the aspect has already flashed
and not before: that’s why the finding cannot be anticipated, not
ei?es by the greatest genius. It always comes unbidden and, as it
would seem, in a sudden flash.

To take another case, is the calculation

(5 + 3)2::::, 52 ^2. 5. 3 + 32

at the same time a proof that

(2 + 3)-=:22+2.2.3~f-3^ ?

Yes and no— depending on how you look at it. (Does it strike you
that the 2 in the middle term is a ‘‘stracturar’ 2, deriving not from
the special numbers but from the general form of the operation?)
A man, while reckoning with special numbers only, may yet con-
ceivably do algebra if he sees the special sums in a new way, as the
expressions of a general iav\ (Discovery^ of algebra as the discovery
of an aspect of numerical calculation.)

What goes for these more or less trivial cases goes for Descartes
and also for Einstein and Hilbert. They were unable to seek, Einstein
for a conceptual gap in the idea of simultaneity, Hilbert for the
axiomatic method. Though these discoveries are of a different order
altogether, the principle underlying them is the same. None of them
has ever “arrived” at his view because he was never travelling. They
did not seek, they found (like Picasso). And tliat is so wrong with
the whole way in which such discoveries are so often presented — as
if they were ^e result of a “method” or “procedure,” as if the great
men arrived at their solutions by drawing logical inferences. This
leaves out the most essential thing — the flashing of a new aspect
which is non-inferential. The moments of seeing cannot be foreseen,
any more than they can be planned, forced, controlled, or sum-
moned by will-power.

Is there any truth in what I am saying? I shall not argue. In-
stead, let me remind you of some observations which will be familiar
■ to you. It is notorious that a philosophy is not made, it grows. You
choose a puzzle, you are shocked into it. Whoever has pon-
some time over some dark problem in philosophy will have
;^ficed that the solution, when it comes, comes with a suddenness.
It is not through working very hard tow^ards it that it is found. What
' is rather that he suddenly sees things in a new light — as if

^ veil had been lifted that screened his view, or as if the scales bad

[ 380 ] FKIEDUICH WAISMANK

faHen from Ms eyes, leaviog Mm surprised at Ms own stupidity not
to have seen what was there quite plain before him all the tkne. It
is less like finding out something and more like maturing, outgrow-
ing preconceived notions.

To give just one example of vision in philosophy: Wittgenstein
saw through a big mistake of Ms time. It was then held by most
philosophers that the nature of such things as hoping and fearing,
or intending, meaning and understanding could be discovered throng
introspection, while others, in particular psychologists, sought to
arrive at an answ^er by experiment, having only obscure notions as
to what their results meant. Wittgenstein changed the whole approach
by saying: what these words mean shows itself in the way they are
used — the nature of understanding reveals itself in grammar, not in
experiment. This was at the time quite a revelation and came to
him, so far as I remember, suddenly.

The view advocated here is that at the living center of every philos-
ophy is a vision and that it should be judged accordingly. The really
important questions to be discussed in the Mstory^ of philosophy are
not whether Leibniz or Kant were consistent in arguing as they did
but rather wmat lies beMnd the systems they have built. And here I
want to end with a few words on metaphysics.

To say that metaphysics is nonsense is nonsense. It fails to
acknowledge the enormous part played at Ieasf"in the past by those
systems. Why this is so. why they should have such a hold over the
human mind I shall not undertake here to discuss. Metaphysicians,
like artists, are the antennae of their time: they have a flair for
feeling which w^ay the spirit is moving. (There is a Rilke poem about
it.) There is sometmng visionaiy about great metaphysicians as if
they had the power to see beyond the horizons of their time. Take,
for instance, Descartes' work. That it has given rise to endless meta-
physical quibbles is certainly a thing to hold against it. Yet if we
attend to the spirit rather than to the words I am greatly inclined
to say that there is a certain grandeur in it, a prophetic aspect of the
comprehensibility of nature, a bold anticipation of what has been
achieved in science at a much later date. The true successors of
Descartes were those who translated the spirit of this philosophy
into deeds, not Spinoza or Malebranche but Newton and the mathe-
matical description of nature. To go on with some hairsplitting as
to what substance is and how it should be defined was to miss the
message. It wus a colossal mistake. A philosophy is there to be
lived out. WhdX goes into the word dies, what goes into the work lives.

Bibliography of Logical Positivism

1

The range of this bibliography is rather wider than that of the
{jook. It includes works which are either expository or critical not
only of logical positivism, in the strict sense, but of every form of
jxjodem analytical philosophy. It does not claim to be exhaustive even
on the topic of logical positivism: but an effort has been made to
list at any rate the most important books and articles that can rea-
sonably be regarded as falling within this field.

The bibliography is divided into three sections: anthologies and
compilations; books and monographs; and articles, including contri-
butions to symposia and critical notices of special interest. Contribu-
tions by any one writer are listed in chronological order. The refer-
ences to articles do not give the numbers of the periodicals or
proceedings in which they appear, but the dates oi the volumes in
which these numbers fall. This is in conformitv' with the practice fol-
lowed by the other books in this series.

ANTHOLOGIES
A N D C O M P I L A T I 0 N S

Ayer, A. J. el al. The Revolution in Philosophy, London: Macmillan, 1956
BlacL M. (ed.). Philosophical Analysis, Ithaca: Cornel! Univ. Press, 1950
Hdwards, P. and Pap, A. (eds.), A Slodern Introduction to Philosophy, Glen-
coe: The Free Press; London: Allen and Umtin, 1957
ISton, W, (ed.). Aesthetics and Language, Oxford: Basil Blackwell, 1954
Feigl, H.-and Brodbeck, M. (eds.). Readings in the Philosophy of Science,
New York: Appleton-Century-Crofts, 1953 , ,, , j

' IBdgi, H. and Scriven, M. (eds.), Minnesota Studies in the Philosophy of
' ■ Science; Vol. I, The Foundations of Science and the Concepts of
L ' Psychology and Psychoanalysis, Minneapolis : Univ. oi Minnesota

■ Press, 1956

[ 3S2 ] Bibliography of Logical Positivism

Feigl, H., Scriven, M. and Ma?well, G- (eds.), Minnesota Studies in the Phi.

losophy of Science; Vol. II, Concepts, Theories, and the Mind-Body
Problem, Minneapolis : Univ. of Minnesota Press, 1958
Feigi, H. and Sellars, W. (eds.), Readings in Philosophical Analysis, New
York: Appieton-Century-Crofts, 1949

Flew, A. G. N. (ed.). Logic and Language (first series), Oxford: Blackwell
1951

Logic and Language (second series), Oxford: BiackweE, 1953
Essays in Conceptual Analysis, London: Macmilian, 1956
Flew, A, and MacIntyre, A. (eds.), New Essays in Philosophical Theology^
London: SCM Press; New York: Macinilian, 1955
Gardiner, P. (ed.). Theories of History, Glencoe: The Free Press, 1959
Henie, P., Kailen, H. M. and Langer, S. K. (eds.), Structure, Method and
Meaning: Essays in honor of Henry M. Shefer, New York: Liberal
Arts Press, 1951

Hook, S. (ed.), American Philosophers a: Work, New York: Criterion Books
1956

Determinism and Freedom, New York: New" York Unrv'. Press, 1958
International Encyclopedic of Unified Science, ed. 0. Nenrath and others:

(combined ed.), vol. I in 2 parts. Chicago: Univ. of Chic. Press, 1955
Lasiett, P. (ed.). The Physical Basis of Mind, Oxford: Blackwell, 1950
Politics, Philosophy and Society, Oxford: Blackwell. 1956
Lewis, H- D. (ed.). Contemporary British Philosophy (third series), London:
Alien and Unwin, 1956

Linsky, L. (ed.), Semantics and the Philosophy of Language, Urbana: Univ.
of lilinois Press, 1952

Macdonald, M. (ed.). Philosophy and Analysis, Oxford: Blackwell, 1954
Mace, C- A. (ed.), British Philosophy in the Mid-Century, London: Allen
and Unwin; New" York: Macmillan, 1957 v
Mitchell, B. (ed.), Faith and Logic, London: Allen and Unwin, 1957
Muirhead, 1. H. (ed.). Contemporary British Philosophy (first and second
series), London: Alien and Unwin, 1924 and 1925
Munitz, M. K. (ed.), A Modern Introduction to Ethics, Glencoe: The Free
Press, 1958

Nenrath, O., ei aL, Encyclopedia and Unified Science. Chicago: Univ. of
Chic. Press (Int. Encyci. of Unified Science). 1958
Pears, D. F. (ed.), The Nature of Metaphysics, London; \fa rrnil l an .. 1957
Runes, D. (ed.), Twentieth Centura Phliosophy, New \'ork: Philosophical
Libraiy’, 1943

Schilpp, P. A. (ed.). The Philosophy of G. E. Moore, Evanston: Northwest-
ern Univ., 1942; 2nd ed. 1*952

The Philosophy of Bertrand Russell. Evanston: Northw’esiem Univ., 1944
Albert Einstein: Philosopher-Scieniis:, New York; Tudor Press, 1949
Sellars, W. and Hospers, J. (eds.). Pleadings in Ethical Theory, New York:
Appieton-Century-Crof ts, 1952

Philosophical Studies, Essays in Memory of L. Susan Stebbing, London:
Alien and Unwin, 1948

Wiener, P. P. (ed.). Readings in PhilosoDh^ of Science, New York: Scribner’s,
1953

Philosophical Essays for A, N. Whitehead, London: Longman’s, 1936

of Logical Positivism

[ 383 ]

BOOKS

K-, Beiiriige zur Methodologie der deduktiven Wissenschaften,
Lwow: Veriag der Polnischen PMIosophischen Geselischaft in Lem-
berg, 1921

Afiscombe, G- E. M., Intention, Oxford: Basil Blackweli, 1957
Austin, J. L., Ifs and Cans, British Academy Armnai Philosophical Lecture,
London: Oxford Univ. Press, 1956

tycr, A. I., Language, Truth and Logic, London: Gollancz, 1936, 2nd ed. 1946
The Foundations of Empirical Knowledge, London: Macmillan, 1940
Thinking and Meaning, London: H. K. Lewis, 1947
Philosophical Essays, London: Macmillan, 1954

The Problem of Knowledge, London: Macmillan and Penguin Books, 1956
Baier, K., The Moral Point of View, Ithaca: Cornell Univ. Press, 1958
Barnes, W. H. F., The Philosophical Predicament, London: A. and C. Black,
1950

Bergmarm, G., The Metaphysics of Logical Positivism, London: Longmans,
Green, 1954

Philosophy of Science, Madison: Univ. of Wisconsin Press, 1957
Black, M., The Nature of Mathematics, London: Kegan Paul; New York:
Harcourt Brace, 1933

Language and Philosophy, Ithaca: Cornell Univ. Press, 1949
Critical Thinking, New York: Prentice Hall, 1952
Problems of Analysis, London: Routledge and Kegan Paul, 1954
Bloomfield, L., Linguistic Aspects of Science, Chicago: Univ. of Chic. Press,
(Int Encycl. of Unified Science), 1939
Bochenski, I. M., Europdische Philosophie der Gegenwart, Bern: Francke,
1947. Eng- transL by D. Nichoil and K. Aschenbrenner, Contem-
porary European Philosophy, Berkeley: Univ. of California Press, 1956
Precis de Logique Maihematique, Bussum: F. G. Klroonder, 1949
Braithwaite, R. B., Scientific Explanation, Cambridge: Cambridge Univ.
Press, 1953

Bridgman, P. W., The Logic of Modern Physics, New York: Macmillan, 1927
The Nature of Physical Theory, Princeton: Princeton Univ. Press, 1936
Reflections of a Physicist, New York: Philosophical Library', 1950
Britton, K., Communication: A Philosophical Study of Language, London:

Routledge and Kegan Paul, 1939
Broad, C. D., Scientific Thought, London: Kegan Paul, 1923

The Mind and Its Place in Nature, London: Kegan Paul, 1925
R., Der Raum, Berlin: Erg. Heft 56 der Kantstudien, 1922
Der logische Aufbau der Welt, Berlin: Weitkreis- Veriag, 1928
Scheinprobleme in der Philosophie, das Fremdpsychische und der Real-
ismusstreit, Berlin, 1928
Abriss der Logistik, Vienna: Springer, 1929

Logische Syntax der Sprache, Vienna: Springer, 1934. Eng. transL, Logi-
cal Syntax of Language, London: Kegan Paul; New York: Harcourt
Brace, 1937

[ 384 ] Bibliography of Logical Positivism

Carnap, R. {continued)

Die Aufgabe der Wissenschaftslogik, Einheitmissenschcft, No. 3, Vienaa:
Gerold, 1934. French transl. (together ^th that of “FornialwisstD-
schaft imd Realwissenschaft,” see articles below), Le probieme de
la logique de la science, science formelle et science du reel, Paris:
Actuaiites Scientifiqnes 291, Herman, 1935
Philosophy and Logical Syntax, London: Kegan Paul, 1935
Foundations of Logic and Mathematics, Chicago: Univ. of Chic. Press
(Int Encycl. of Unified Science), 1939
Introduction to Semantics (Studies in Semantics, voL I), Cambridge;
Harvard Univ. Press, 1942

Formalization of Logic (Studies in Semantics, voL 11), Cambridge: Har-
vard Univ. Press, 1943

Meaning and Necessity: A Study in Semantics and Modal Logic, Chi-
cago: Univ. of Chic. Press, 1947

Logical Foundations of Probability (Probability and Induction, voi. I),
Chicago: Univ. of Chic. Press, 1950
The Nature and Application of Inductive Logic (sk sections from Logical
Foundations of Probability), Chicago: Univ. of Chic. Press, 1951
The Continuum of Inductive Methods, Chicago: Univ. of Chic. Press, 1952
Einfuhrung in die symbolische Logik, mil besondersr Berucksickiigung
ihrer Anwendungen, Vienna: Springer, 1954. Engl, transl. Introduc-
tion to Symbolic Logic, New York: Dover, !95S
Carnap, R. and Bar-Hillel, Y., An Outline of the Theory of Semantic Informa-
tion, Cambridge: Res. Lab. of Electronics, hi. IT. Repon No. 247,
1952

Carnap, R.. Hahn, H. and Neurath, O., Wissenschaftliche V/ehaunassung: Der
Wiener Kreis, Vienna: Wolf, 1929

Chisholm, R. M., Perceiving: A Philosophical Study. Ithaca: Comeii Univ,
Press, 1957

Clauberg, K. W. and Dubislav, W., Systematisches Worterbuck der Philo^
sophie, Leipzig: Meiner, 1923

Copleston, F., Contemporary Philosophy, London: Bums and Oates, 1956
Comforth, M., Science versus Idealism, London: Lawrence and Wishart, 1946
In Defence of Philosophy against Positivism arid PragrTmtism, London:
Lawrence and Wishart, 1950

Dray, Wl, Laws and Explarmtion in History, O.xiord: Oxford Univ. Press, 1957
Dubislav, W., Vber die sog, analytischen und synmeiischen Vrieile, Berlin,
1926

Vber die Definition, Berlin, 1927

Die Philosophic der Mathematik in der Gegenwari, Berlin: Dunker k
Dunnhaupt, 1932

Dubislav, W. and Clauberg, K. W., Systematisches Worterbuck der Philo-
sophie, Leipzig: Meiner, 1923

Edwards, P., The Logic of Moral Discourse, Glencoe: The Free Press, 1955
Einstein, A., Geometrie und Erfahrung, Berlin: Springer, 1921
Ewing, A. C., The Definition of Good, New Y^'ork: Macmillan, 1947
Feigl, H., Theorie und Erfahrung in der Pkysik, Karisnihe: Braun, 1929
Finiay-Freundiich, E., Cosmology, Chicago: Univ. of Chic. Press (Ink Encycl
of Unified Science), 1951

Frank, P., Das Kausalgesetz und seine Grenzen, Yuemia: Springer, 1932

Das Ende der mechanistischen Physik, Einkeitswissenschaft No. 5, Vienna:
Gerold, 1935

tv-}'.;.

'v:.. %
S.:

k'i

t

^iUdgraphy of Logical Positivism [ 385 ]

P* (continued)

-^JMerpretations and Misinterpretations of Modern Physics, Pans: Her-

... * - maas, 1938

" - Between Physics and Philosophy, Cambridge: Har\'ard Univ. Press, 1941
. ' Bamdations of Physics, Chicago: Univ. of Chic. Press (Int. Encycl. of
' Unified Science), 1946

B.is Life and Times, New York: Knopf, 1947; London: Jona-
W - f ban Cape, 1948

" Modem Science and Its Philosophy, Csiiahndge: PlaTVBiTdXJniv, Press, 1949

Melativity: A Richer Truth, Boston: Beacon Press, 1950; London: Cape,
, 1951

: : Philosophy of Science, Englewood Cliffs: Prentice-Hall, 1957
%ardiner, P., The Nature of Historical Explanation, Oxford: Oxford Univ.
Press, 1952

^ ' Uoodman, N., The Structure of Appearance, Cambridge: Harvard Univ.

Press, 1951

Fact, Fiction and Forecast, London: Athione Press, 1954; Cambridge:
Harvard Univ. Press, 1955

Hahn, H., Vberfiiissige Wesenheiten, Vienna: Wolf, 1929

Logik, Mathematik und Naturerkennen, Einheitswissenschaft No. 2,
Vienna: Gerold, 1933. Eng. transl. in the present volume
Hahn, H., Camap, R. and Neurath, O., Wissenschaftliche Wehauffassung:
r Der Wiener Kreis, Vienna: Wolf, 1929

' Hallden, S. L, The Logic of Nonsense, Uppsala: Bokhandeln A-B. Lunde-
- ■ . . quistska, 1949

Emotive Propositions, Stockholm: Almqvist & W^iksell, 1954
Hare, R. M., The Language of Morals, Oxford: Clarendon Press, 1952
' Hart, H. L, A., Definition and Theory in Jurisprudence, Oxford: Clarendon
Press, 1953

Helmholtz, H. von, Schriften zur Erkenntnistheorie, ed. Scblick, M. and
Hertz, P., Berlin: Springer, 1921

^ Hempel, C. G., Fundamentals of Concept Formation in Empirical Science,
Chicago: Univ. of Chic. Press (Int. Encycl. of Unified Science), 1952
' ’■ * Hempel, C. G. and Oppenheim, Der Typusbegriff im Lichte der neuen
Logik, Leiden; Sijthoff, 1936

Hill, T. E., Contemporary Ethical Theories, New York: Macmillan, 1950
Holloway, I., Language and intelligence, London: Macmillan, 1951
Hospers, J., Meaning and Truth in the Arts, Chapel Hill: Univ. of North Caro-
lina Press, 1946

A . . An Introduction to Philosophical Analysis, New York: Prentice-Hall, 1953
; . Huttcn, E. H., The Language of Modern Physics, London: Alien and Unwin,
15>.56

C. E. M., A Critique of Logical Positivism, London: GoUancz; Chicago:
Univ. of Chic, Press, 1950

V .1;.- \^<ttdan, Z., On the Development of Mathematical Logic and of Logical Posi-
in Poland, London: Oxford Univ. Press, 1946
^ Treatise of Formal Logic, Copenhagen: Levin & Mimksgaard;

. London: Humphrey Milford (Oxford Univ. Press), 1931
Peykologi Paa Biologisk Grundlag (Psychology Based on Biology), Co-
penhagen, 1941-45

’Pke Development of Logical Empiricism, Chicago: Univ. of Chic. Press

'i-

(Int. Encycl. of Unified Science), 1951

[ 386 ] Bibliography of Logicd Fositivism

Kalia, E., Der Logistische Neupositivismus: Eine kritische Studie, Tnrkii:
Tnnin Yiiopiston jnlkaisuja, 1930

t)ber das System der Wirklichkeitsbegriffe, Helsinki: Acta PMosopMca
Feimica, Fasc. 2, 1936

tJber den physikalischen Reaiitdtsbegriff, Helsinki: Acta PMosopMca
Fennica, 3Fasc. 4, 1941

Terminal-Kausalitdt als die Grundlage eines unitarischen Naturbegriffs:
eine naturphilosophische XJntersuchung, Helsinki: Acta PMlosophica
Fennica, 1956

Kanfmann, F., Das Unendliche in der Mathematik und seine Ausschaltung,
Vienna: Deuticke, 1930

Methodology of the Social Sciences, London: Oxford Univ. Press, 1944

Kelsen, H., Vergeltung und Kausalitdt, The Hague: van Stockum, 1941. Eng.

transl. Society and Nature, Chicago: Univ. of Chic. Press, 1943;
London: Kegan Paul, 1946

Kneale, W., Probability and Induction, Oxford: Clarendon Press, 1949

Kotarbinski, T., Elementy teori poznania, logiki formalnej i metodolog: nauk
(Elements of the theory of knowledge, formal logic and method-
ology of science), Lwow, 1929

ICraft, V., Die Grundlagen einer wissenschaftlichen Werilehre, Vienna:
Springer, 1937

Mathematik, Logik und Erfahrung, Vienna: Springer, 1947
Einfuhrung in die Philosophie — Philosophie, Weltanschauung,
schaft, Vienna: Springer, 1950

Der Wiener Kreis, Der Ursprung des Neupositivismus, Vienna: Springer,
1950. Eng. transL, The Vienna Circle, New York: Philosophical
Library, 1953 ^ ‘

Lazerowitz. M., The Structure of Metaphysics, London: Routiedge and Kegan
Paul, 1955

Lean. M., Sense -Perception and Matter, London: Routiedge and Kenan
Paul, 1953 .

Lewis, C. I., Mind and the World Order, New York: Scribner, 1929

An Analysis of Knowledge and Valuation, La Salle: Open Court. 1946

Lukasiewicz, J., Die iogischen Grundlagen der Wahrscheinlichkehsrschnung,
Cracow': Krakauer Akad. d. Wiss., 1913
O nance (On Science), Lwow% 1934

Mainx, F., Foundations of Biology, Chicago: Univ, of Chic. Press (ini. En*
cyci, of Unified Science), 1955

Malcolm, N., Ludwig Wittgenstein: A Memoir, Oxford and New' York: Ox-
ford Univ. Press, 1958

Marc-Wogau, K., Die Theorie der Sinnesdaten, Uppsala: Universiieis Ars-
skrift, 1945

von Mises, R., Wahrscheinlichkeit, Statistik und Wahreii, Vienna: Springer,
1936. Eng. transl.. Probability, Statistics and Truth, New' York: Mac-
millan; London: William Hodge, 1939
Ernst Mach und die empiristische Wissenschaftsauffassung, Einheitswis-
senschaft No. 7, ’s Gravenhage: W. P. van Stockum, 1938
Kleines Lehrbuck des Positivismus, The Hague: Van Stockum & Son,
1939. Eng. transL, Positivism: A Study in Human Understanding,
Cambridge: Harvard Univ. Press, 1951

Moore, G. E., Principia Ethica, Cambridge: Univ. Press, 1903
Ethics, London: Home University Library, 1912

Positivism [ 387 ]

p^^flv^rMoons, G. E. (continued)

philosophical Studies, London: Kegan Paul, 1922
7- ^ -p/w?# of an External World, British Academy: Animal PMasophical

/■ Lecture, 1939

'"■/‘'Jif ? ^^jne Main Problems of Philosophy, London: Allen and Unwin, 1953

Moms, C- W., Logical Positivism, Pragmatism, and Scientific Empiricism,
\ - “ Paris: Hermann, 1937

J 'p; “ foundations of the Theory of Signs, Chicago: Unlv. of Chic. Press (Int.

/ . r- BncycL of Unified Science), 1938

r, * J S^ns, Language, and Behavior, New York: Prentice-Hail, 1946
Naess, A-, Erkenntms und Wissenschaftliches Verhalten, Oslo: 1936
’ ' ^ ' **Truth** as Conceived by Those Who Are Not Professional Philosophers,

y . Oslo; 1938

1'- Interpretation and Preciseness, Oslo: 1953

~ Innforing, Logikk og Metodelaere, Oslo: Universitets Studentkontor, 1949
I: Naess, A., Christophersen, J. A. and Kvalo, K., Democracy, Ideology and

Objectivity: Studies in the Semantics and Cognitive Analysis of
Ideologic^ Controversy, Oslo: Univ. Press; Oxford, Blackwell, 1956
Nagel, £., On the Logic of Measurement, New York: Columbia Univ. Ph.D.
Thesis, 1930

Principles of the Theory of Probability, Chicago: Univ. of Chic. Press
(Int Encycl. of Unified Science), 1939
, . Sovereign Reason, Glencoe: The Free Press, 1954

Logic Without Metaphysics, Glencoe: The Free Press, 1956
Nagel, E, and Newman, J. R., GodeVs Proof, New' York: New' York Univ,
Press, 1958

Nearath, O., Antispengler, Munich: Cailwey, 1921
Empirische Soziologie, Vienna: Springer, 1931

Einheitswissenschaft und Psychologic, Einheitswissenschaft No. 1, Vienna:
Springer, 1933

Le developpement du Cercle de Vienne et Vavenir de Vempirisme logique,
|.; Paris: Hermann, 1935

' Was Bedeutet Rationale Wirtschaftsbetrachtung? , Einheitswissenschaft

I No. 4 , Vienna: Gerold, 1935

- Foundations of the Social Sciences, Chicago: Univ. of Chic. Press (Int

Encycl. of Unified Science), 1944

Neurath, 0-, Brunswik, E., Hull, C. L., Mannour>', G. and Woodger, J. H.,
Zur Encyklopddie der Einheitswissenschafi, Vortrdge, Einheitswis-
senschaft No. 6, ’s Gravenshage: W. J, von Stockum, 1938
. - . Neurath, O., Carnap, R. and Hahn, H., Wissenschaftliche W eltauffassimg:

- * Der Wiener Kreis, Vienna: Wolf, 1929

J. R, and Nagel, E., GodeVs Proof, New York: New York Univ.
-■’..■'4-'. ^ Press, 1958

' l^cod,!.. Foundations of Geometry and Induction, London: Kegan Paul, 1930

Noweii-Smith, P, H., Ethics, London: Penguin, 1954; Oxford: Blackwell, 1958
:j C, K. and Richards, I. A., The Meaning of Meaning, London: Kegan

* ^Paui, 1923

^ " Qppenheim, P., Die Naturliche Ordnung der Wissenschaften. Grundgesetze
' ' der vergleichenden Wissenschaftslehre, Jena: Gustav Fischer, 1926

. I^%»enhemi, P. and Hempel, C. G., Der Typusbegriff im Lichte der neuen
Logik, Leiden: Sijthoff, 1936

[ 388 ] Bibliography of Logical Positivism

Pap, A., The A Prion in Physical Theory, New York: King’s Crown Press,
1946

Elements of Analytic Philosophy, New York: Macmillan, 1949
Analytische Erkenntnistheorie, Vienna: Springer-Verlag, 1955
Semantics and Necessary Truth, New Haven: Yale Univ. Press, 1958
Passmore, J., A Hundred Years of Philosophy, London: Duckworth, 1957
Pereiman, C. and Olbrechts-Tyteca, L., Traite de 1’ Argumentation (La nouvelle
rhetorique), Paris: Presses Universitaires de France, 1958
Petzall, A., Her Logistische Neupositivismus, Annales Universitatis Aboeasis,
Ser. B., Tom. XIH, 1930

Logistischer Positivismus, Goteborgs Hogskolas Arsskrift XXXVII, Gote-
borg: Wettergren k Kerbers, 1931

Pole, D., The Later Philosophy of Wittgenstein, London: Athlone Press, 1958
Popper, K. R., Logik der Forschung, Vienna: Springer, 1935. Eng. trans!.,
The Logic of Scientific Discovery, London: Hutchinson, 1958
The Open Society and Its Enemies, London: Kegan Paul, 1945
The Poverty of Historicism, London: Routiedge and Kegan Paul, 1957
Price, H. H., Perception, London: Methuen, 1932

Truth and Corrigibility, Inaugural Lecuire, London: Oxford Univ, Press,
1936

Hume's Theory of the External World, Oxford: Clarendon Press, 1940
Thinking and Representation, British Academy Lecture, 1946
Thinking and Experience, London: Hutchinson, 1953
Quine. W. V. O., From a Logical Point of View, Cambridge: Harvard Univ.
Press, 1953

Ramsey. F. P., The Foundations of Mathematics anil Other Logical Essays,
London: Kegan Paul, 1931

Reicbenbach, H-, Reiaiivitdtstheorie und Erkenntnis A priori, Berlin: Springer,
1920

Axiomatik der relativistischen Raum-Zeii-Lehre {Die Wissenschaft No.
72), Braunschweig: Vieweg, 1924

Philosophic der Raum-Zeit-Lehre, Berlin and Leipzig: Walter de Gruyter,
1928. Engl. transL, The Philosophy of Space and Time, New York;
Dover, 1957

Atom und Kosmos. Das physikalische V/eltbild der Gegenwart, Berlin:
Deutsche Buch-Gemeinschaft, 1930. Eng. transl., Atom and Cosmos.
The World of Modern Physics, London: Allen and Unwin, 1932;
New York: Macmillan, 1933

Ziele und Wege der keutigen Naturphilosophie, Leipzig: Meiner, 1931.
Eng. transl- in Selected Essays, London: Routiedge and Kegan Paul,
1959

Wahrscheinlichkeitslehre. Bine Untersuchung ilber die logischen und
mathemaiischen Grundlagen der Wahrscheinlichkeitsrechnung, Lei-
den: Sijthoff, 1935. Eng. transl.. The Theory of Probability. An
Inquiry into the Logical and Mathematical Foundations of the Cal-
culus of Probability, 2nd ed., Berkeley and Los Angeles: Univ. of
California Press, 1949

Experience and Prediction. An Analysis of the Foundations and the
Structure of Knowledge, Chicago: Univ. of Chic. Press, 1938
Philosophic Foundations of Quantum Mechanics, Berkeley and Los An-
geles: Univ. of California Press, 1944. Ger. transl., Basel: Birk-
bauser, 1949

'^"^ B^graphy of Logical Positivism [ 389 ]

\ lijMiefibacIi, H. {continued)

,, .; ^"^^Ismenis of Symbolic Logic, New York: Macmilian, 1947

The Rfee of Scientific Philosophy, Berkeley and Los Angeles: Univ. of
Califonila Press, 1951. Ger. transL, Berlin-Gninewald: Herbig, 1953
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1921

The Analysis of Matter, London: Kegan Paul, 1927
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1927

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Simon and Schuster, 1946

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New York: Simon and Schuster, 1948
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ScMick, M. (continued)

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Ethics, New York: Prentice-Hall, 1939
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Philosophy and the Physicists, London: Methuen, 1937
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Stroll, A., The Emotive Theory of Ethics, Berkeley: Univ, of California
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Tarski, A.., Einjuhrung in die Mathematische Logik und die Methodologie
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Urmson, J. O., Philosophical Analysis, Oxford: Clarendon Press, 1956
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Weinberg, J. K., An Examination of Logical Positivism, London: Kegan Paul;

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ARTICLES
The foUowing abbreviations are used in this list:

A for Analysis

AJ for Australasian Journal of Psychol-
ogy and Philosophy

Arch. F. Sy. Phil, for Archiv fur Sys-
temadsche Philosophic
ArSoc. for Proceedings of the Aristote-
lian Society

Ar.Soc.Sup. for Proceedings of the Aris-
totelian Society, Supplementary
Volumes

BJPS for The British Journal for the
Philosophy of Science
E for Erkenntnis
HI for Hibbert Journal
JP for Journal of Philosophy

JSL for Journal of Symbolic Logic
JUS for Journal of Unified Science
M for Mind
P for Philosophy

PPR for Philosophy and Phenomenologi-
cal Research

PQ for Philosophical Quarterly
PR for Philosophical Review
PS for Philosophy of Science
PSt for Philosophical Studies
Psych. Pc',', for Psychological Review
Rev.Int.Pkil. for Revue Internationale de
Piiilosophie

RM for Reviev.- of Metaphysics
T for Theoria

Acton, H. B., “The Expletive Theon* of Morals,” A., 1936-37
“Is Ethical Relativity Necessary?” Ar.Soc.Sup.. 193S
“Moral Subjectivism,” A, 1948-49

Adams, E. M., “A Critique of the Emotive Theory of Ethical Terms,” JF, 1949
“Word-Magic and Logical Analysis in the Field of Efnics.” IP, 195G
Aiken, K. D., “Emotive ‘Meanings’ and Ethical Terms,” JF, 1944
“Stevenson’s Ethics and Language T JP, 1945

“Evaluation and Obligation: Two Functions of judgments in the Lan-
guage of Conduct,” JP, 1950. Reprinted in Sellars, H. and Hospers,
J., Readings in Ethical Theory
“The Authority of Moral Judgments,” PPR, 1951-52
“Dennitions, Factual Premises and Ethical Conclusions.” PR, 1951
“The Role of Conventions in Ethics,” JF, 1952
Aidukiewicz, K.. “Zalozenia logiki tradycyjnej” (Assumptions of Traditional
Logic), Frzegiad FUozoficzny, 1926-2?

“Sprache und Sinn,” E, 1934
“Das W'eltbild and die Begriffsapparatur,” E, 1934
“Der iogistische Antiirationaiismus in Polen,” E, 1935-36
“Die syntaktische Konnexitat,” Stadia Philosophica, 1935
“W sprawie powszechnikow” (On Universals), Przeglad FUozoficzny, 1935
“Die wissenschaftliche Weltperspektive,” E, 1935. Reprinted in English
translation in Feigi, H. and Sellars, W., Readings in Philosophical
Analysis

“Logic and Experience,” Synthese, 1950-51
Aldrich, V. C., “Symbolization and Similarity,” Monist, 1932

“A Note on the Empirical Meaning of ‘possible’,” A, 1936-37
“Some Meanings of ‘Vague’,” A, 1936-37

“Messrs. Schlick and Ayer on ImmonaJity,” PR, 1938. Reprinted in
Feigi, H. and Sellars, W., Readings in Philosophical Analysis
“The Spirit of the New Positivism,” JP, 1940

The Philosophy

.if?-&r ^rl

jkbSography of Logical Positivism [ 393 ]

' '' Aldrich, V. C. {continued)

'■ '-.,-'^^«pictorial Meaning and Picture Thinking,** Kenyon Review, 1943. Re-
■' printed in FeigI, H. and Seliars, W., Readings in Philosophical

^ ’ Analysis

' 4 " >. . ‘Xanguage, Experience and Pictorial Meaning/* /P, 1948

*®The Informal Logic of the Employment of Expressions,” PR, 1954
**TheLast Word on Being Red and Blue All Over,” PSt, 1954
; / ‘The Origin of the AprioriT JPf 1954
-“What Appears?,” PR, 1954
Ts an After-Image a Sense-Datum?,” PPR, 1954-55
“Mr^ Quine on Meaning, Naming, and Purporting to Name,” FSl, 1955
“Expression by Enactment,” PPR, 1955-56
. : Alexander, H. G., “Necessary Truth,” M, 1957

' Alexander, P., “Other People’s Experiences,” Ar,Soc., 1950-51
“Complementary Descriptions,” M, 1956
AJston, W. P., “Are Positivists Metaphysicians?,” PR, 1954
“Particulars — Bare and Qualified,” PPR, 1954-55
“Pragmatism and the Verinability Tneory of Meaning,” PSt, 1955
Tneffabiiity,” PP, 1956

Ts a Sense-Datum Language Necessar>'?,” PS, 1957
Ambrose, A., “Finitism in Mathematics, I and U,” M, 1935

“Moore’s Proof of an External World,” in Schilnp. P. A-, The Philosophy
of G. E, Moore, 1942
“Self-contradictory Suppositions.” M. 1944

“The Problem of Justifying Inductive Inference,” JP, 1947. Reprinted in
Hook, S., American Philosophers a: IVork
“Everett J. Nelson on The Relation of Logic to Metaphysics/” PR, 1949
“Hie Problem of Linguistic Inadequacy/' in Black, M,. Philosophical
Analysis, 1950

“Linguistic Approaches to Philosophical Problems,” JP, 1952
“Wittgenstein on Some Questions in the Foundations of Mathematics/’
JP, 1955

“On Entailment and Logical Necessity,” Ar.Soc.. 1955-56
Anderson, J., “The Meaning of Good,” AJ, 1942
“Hypotheticals,” AJ, 1952

Anscombe, G. E. M., “The Reality of the Pasi,” in Black. M.. Philosophical
Analysis, 1950

“The Principle of individuation/' Ar.SccSuv., 1955
“Aristotle and the Sea Battle,” M, 1956
“intention,” ArSoc., 1956-57
' T “Pretending,” ArSocSup., 1958

Armstrong, J. H., “Knowledge and Belief,” .4, 1952-53
: Ashby, R. W., “Use and Verification,” ArSoc., 1955-56

von Aster, E., “Kritischer Objekiivismus und Neopositivismus.” J, 1950
“Physikaiistischer und Psychologistischer Positivismus/' T, 1950
, Atkinson, R. F-, “ ‘Good’ and ‘Right* and ‘Probable’ in Language, Truth and
■ *;/ ■ ^ LogicT M, 1955

u Anstm, J. L., “Are There A Priori Concepts?,” Ar.SocSup., 1939

“Other Minds,” Ar.SocSup., 1946. Reprinted in Flew, A., Logic and
. ’ Language (second serf's)

: ArSocSup., 1950

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in Black, hi.. Philosouhical

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Atsstm, J. L. {continued)

“A Plea for Excuses,” ArSoc., 1956-57
“Pretending,” ArSocSup., 1958
Ayer, A. J., “Atomic Propositions,” A, 1933-34

“The Genesis of Metaphysics,” A, 1933-34. Reprinted in Macdonald, M.
Philosophy and Analysis

“On Particulars and Universals,” ArSoc., 1933-34
“Demonstration of the Impossibility of Metaphysics,” M, 1934. Reprinted
in Edwards, P. and Pap, A., A Modern Introduction to Philosophy
“Internal Relations,” ArSocSup,, 1935

“The Criterion of Truth,” A, 1935-36. Reprinted in Macdonald, M.,
Philosophy and Analysis
“The Principle of Verifiability,” M, 1936

“Concerning the Negation of Empirical Propositions,” E, 1936-37
“Truth by Convention,” A, 1936-'^!

“Verification and Experience,” ArSoc,, 1936-37. Reprinted in the present
volume

“Does Philosophy Analyse Common Sense?,” Ar.Soc.Siip., 1937
“On the Scope of Empirical Knowledge. A Rejoinder to Bertrand Russel! ”
E, 1937-38

“The Terminology' of Sense-Data,” M, 1945. Reprinted in Philosophical
Essays

“Jean-Paui Sartre,” Horizon, 1945
“Albert Camus,” ibid.

“Deistic Fallacies,” Polemic, 1945

“Freedom and Necessity,” Polemic, 1946. Reprinted in Philosophical
Essays

‘The Claims of Philosophy,” Polemic, 1947. Reprinted in Reflections on
Our Age: Unesco, 1948

“Tne Principle of Utility,” in Keeton, G. W. and Schwarzenberger, G.,
Jeremy Bentham and the Law, London: Stevens, 1948. Reprinted in
Philosophical Essays

“Some Aspects of Existentialism,” Rationalist Annual, 1948
“On the Analysis of Moral Judgements,” Horizon, 1949. Reprinted in
Philosophical Essays and in Munitz, M. K., ^ Modern Introduction
to Ethics

“Basic Propositions,” in Black, M., Philosophical Analysis, 195C. Re-
printed in Philosophical Essays

^X)n What There is,” Ar.Soc.Sup., 1951. Reprinted in Fkiiosopkical Essays
“The Philosophy of Science,” in Heath, A. E., Scientific Thought in the
Twentieth Century, London: Watts, 1951
“Statements about the Past,” Ar.Soc., 1951-52. Reprinted in Philosophical
Essays

“Individuals,” M, 1952. Reprinted in Philosophical Essays
“Negation,” JP, 1952. Reprinted in Philosophical Essays
“Cogito Ergo Sum,” A, 1952-53

“The Identity of Indiscemibles,” in Proceedings of the Xhh International
Congress of Philosophy, 1953. Reprinted in Philosophical Essays
“L’immutabilite du passe,” Etudes Philosophiques, 1953
“One’s Knowledge of Other Minds,” T, 1953. Reprinted in Philosophical
Essays

“Truth,” RevJnt.PhiL, 1953

• ^Uography oj Logical Positivism { 395 ]

'kvts A. I- (continued)

«Caii There Be a Private Language?,” ArSocSup.. 1954

Is Communication?,” in Studies in Communication, London: Seeker
and Warburg, 1955

' **Phllosophy at Absolute Zero,” Encounter, 1955
' ■ *What Is a Law of Nature?,” Rev.Int,PhiL, 1956

"Philosoptiical Scepticism,” in Lewis, H. D., Contemporary British Philos-
ophy (third series), 1956

: “Perception,” in Mace, C. A., British Philosophy in the Mid-Century, 1957

^The Conception of Probability as a Logical Relation,” in Observation
and Interpretation: Proceedings of the Ninth Symposium of the
Colston Research Society, 1957

“Meaning and Intentionality,” Proceedings of the Xlltk International
Congress of Philosophy, Venice, 1958
“Pbilosophie et iangage ordinaire,” Dialectica, 1958
Ayer, A. I., and Copieston, F. C., “Logical Positirism — a Debate,” in Edwards,
p! and Pap, A., A Modern Introduction to Philosophy
Bachmann, F. and Carnap, R., “Ober Extremalaxiome,” £, 1936-37
Baier, K., “Objectivity in Ethics,” AJ, 1948
“Decisions and Descriptions,” M, 1951
“The Ordinary Use of Words,” ArSoc., 1951-51:

“Good Reasons,” PSt, 1953
“The Point of View of Morality,” AJ, 1954
“Contradiction and Absurdity,” A, 1954-55
Baler, K. and Touinain, S. E., “On Describing,” M, 1952
Bar-Hiliei, Y., “Analysis of ‘Correct’ Language,” M. 1946
“Comments on Logical Form,” PSt, 1951
“Indexicai Expressions,” M, 1954
“Logical Syntax and Semantics,” Language. 1954
Barnes, W. H. F., “A Suggestion about Value.” .4, 1933-34. Reprinted m
Sellars, W. and Hospers, J., Readings in Etnical Theory
“Meaning and Verifiability,” P, 1939
“The Myth of Sense Data,” Ar.Soc., 1944-45
“Is Phiiosophy Possible? A Study of Logical Positivism." P, 1947
“Ethics Without Propositions,” ArSoeSup.. 194^

“Talking about Sensations,” Ar.Soc., 1953-54

“On Seeing and Hearing,” in Lewis, H. D., C onienivorary British Philos-
ophy (third series), 1956

Barrett, W., “Logical Empiricism and the Histor*’ o: Philosophy,” JF, 1939
“On the Existence of an External World,” JF. 1939
“The Present State of the Problem of induction,” J. i9-r0
Barzin, M., “L’empirisme iogique,” Rev.Ini.PhiL, 1950
Basson, A. H., “The Existence of Material Objects,” M, 1946
“Logic and Fact,” A, 1947-48
“The Problem of Substance,” ArSoc., 1948-49
“The Immortality of the Soul,” M, 1950
‘The Logical Status of Supposition,” ArSoc. Sup., 1951
' ' . “Unsolvabie Problems,” Ar.Soc., 1956-57
Basson, A. H. and O’Connor, D. J., “Language and Phiiosophy,” P, 1947
Baylis, C. A., “Are Some Propositions Neither True Nor False?,” PS, 1936
f r " “Critical Comments on the ‘Symposium on Meaning and Truth,’ ” PPR,
1944-45

1

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I ^

i

I

I

■

Bill®!

' ‘

„ .'-r.t'M

[ 396 ]

PR, 1944

Bayiis, C. A. (continued)

“Facts, Propositions, Exemplification and Tnitli,” M, 194S

“Universais, Communicable Knowledge, and Metaphysics,” /F, 1951

**The Confirmation of Value Judgments,” PR, 1952

“Intrinsic Goodness,” PPR, 1952-53

“Logical Subjects and Physical Objects,” PPR, 1956-57

Beardsley, E., “Imperative Sentences in Relation to Indicatives,” PR, 1944

Beardsley, M., “Phenomenalism and Determinism,” IP, 1942
“Categories,” RM, 1954

Beck, L. W., “Remark on the Distinction between Analytic and Synthetic,”
PPR, 1948-49

“On the Meta-Semantics of the Problem of the Synthetic A priori/" M,
1957

Behman, J., “Sind die mathematischen Urteile analytisch oder synthetisch?,”
E, 1934

Benjamin, A. C., “Outlines of an Empirical Theory of Meaning,” PS, 1936
“The Unholy Alliance of Positivism and Operationalism,” IP, 1942
“On Defining Science,” Scientific Monthly, 1949
“Operationalism — ^A Critical Evaluation,” JP, 1950
“A Definition of ‘Empiricism,’ ” PPR, 1954-55

Bennett, J., “Meaning and Implication,” M, 1954

Bergmann, G-, “On Physicalistic Models of Non-physical Terms,” PS, 1940
“On Some Methcxiological Problems of Psycholog>%” PS, 1940. Re-
printed in Feigl, H. and Brodbeck, M., Readings in the Philosophy of
Science

“The Subject Matter of Psychology,” PS, 1940
“The Logic of Probabiiit>%” American Journal of Pl^ysics, 1941
“An Empiricist Schema of the Psychophysical Problem,” PS, 1942
“Remarks Concerning the Epistemology of Scientific Emniricism,” PS,
1942

“Outline of an Empirical Philosophy of Physics,” American Journal of
Physics, 1943. Reprinted in Feigi, H. and Brodbeck,' M., Readings
in the Philosophy of Science

“An Empiricist’s System of the Sciences,” Scientific Monthly, 1944
“Pure Semantics, ^ntences and Propositions,” M, 1944
“Frequencies, Probabilities and Positivism,” PPR, 1945-46
“Remarks on Realism,” PS, 1946. Reprinted in The Metaphysics of Logi-
cal Positivism

“Some Comments on Carnap’s Logic of Induction,” PS, 1946
“Russell on Particulars,” PR, 1947. Reprinted in The Metaphysics of
Logical Positivism

“Sense Data, Linguistic Conventions and Existence,” PS, 1947. Reprinted
in The Metaphysics of Logical Positivism
“Professor Ayer’s Analysis of Klnowing,” A, 1948-49. Reprinted in The
Metaphysics of Logical Positivism
“Two Criteria for an Ideal Language,” PS, 1949

“On Non-perceptual Intuition,” PPR, 1949-50. Reprinted in The Meta-
physics of Logical Positivism

“Logical Positivism,” in Perm, V., A History of Philosophical Systems,
1950. Reprinted ia The Metaphysics of Logical Positivism
“A Note on Ontology,” PSt, 1950. Reprinted in The Metaphysics of
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Beremann, G. {continued)

‘Two Cornerstones of Empiricism,” Synihese, 1950-51. Reprinted m The
Metaphysics of Logical Positivism

“Logical Atomism, Elementarism and the Analysis of Value,” PS, 1951.

Reprinted m The Metaphysics of Logical Positivism
‘The Logic of Psychological Concepts,” PS, 1951

“Two Types of Linguistic Philosophy,” RM, 1951-52. Reprinted in The
Metaphysics of Logical Positivism

“The Problem of Relations in Classical Psychology,” PQ, 1952. Reprinted
in The Metaphysics of Logical Positivism
“The Identity of Indiscernibles and the Formalist Definition of ‘Iden-
tity/ ” M, 1953. Reprinted in The Metaphysics of Logical Positivism
“Logical Positivism, Language, and the Reconstruction of Metaphysics,”
in Rivisia Critica di Storia della Filosofia, 1953. Reprinted in The
Metaphysics of Logical Positivism

“The Revolt against Logical Atomism,” Parts I and 11, PQ, 1951 and 1958
Berlin, I., “Induction and Hypothesis,” ArSocSup., 1937
“Verification,” Ar.Soc,, 1938-39
“Logical Translation,” Ar.Soc., 1949-50

“Empirical Propositions and Hypothetical Statements,” M, 1950
Black, M., “Philosophical Analysis,” Ar.Soc., 1932-33
“A propos of ‘Facts,’ ” A, 1933-34

“Is Analysis a Useful Method in Philosophy?,” ArSocSup., 1934
“The Principle of Verifiability,” A, 1934-35
‘Truth by Convention,” A, 1936-37

“Vagueness,” PS, 1937. Reprinted in Language and Philosophy
“Some Problems Connected with Language,” ArSoc., 1938-39. Reprinted
as “Wittgenstein’s Tractatuf* in Language and Philosophy
“Relations between Logical Positivism and the Cambridge School of
Analysis,” JUS, 1939-40

“Comments on a Recent Version of Phenomenalism,” A, 1939-40
“Certainty and Empirical Statements,” M, 1942

“Ogden and Richards’ Theory of Interpretation,” JP, 1942. Reprinted in
Language and Philosophy

“Schilpp’s The Philosophy of G. E. MooreP JP, 1943
“The Analysis of a Simple Necessary' StatemenL” JP, 1943
“The ‘Paradox of Analysis,’ ” M, 1944

“Russell’s Philosophy of Language,” in Schilpp, P. A., The Philosophy
of Bertrand Russell, 1944. Reprinted in Language and Philosophy
“The ‘Paradox of Analysis’ Again: a Reply,” M, 1945
“How Can Analysis Be informative?,” PPR, 1945-46
“The Limitations of a Behavioristic Semiotic,” PR, 1947. Reprinted as
“The Semiotic of Charles Morris,” in Language and Philosophy
“The Semantic Definition of Truth,” A, 1947-48. Reprinted in Macdonald,
M., Philosophy and Analysis, and in Language and Philosophy
“Linguistic Method in Philosophy,” PPR, 1947-48. Reprinted in Lan-
guage and Philosophy

“Some Questions about Emotive Meaning,” PR, 1948. Reprinted in JLan-
guage and Philosophy

“Logic and Semantics,” in Philosophical Studies — Essays in Memory of
. Susan St ebbing, 1948. Reprinted in Problems of Analysis as “Car-

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Black, M. {continued)

‘^Carnap’s Semantics,” PR, 1949
“The Definition of Scientific Method,” in Stauffer, R. C., Science and
Civilization, 1949. Reprinted in Problems of Analysis
“The Justification of Induction,” in Language and Philosophy, 1949
“Dn Speaking with the Vulgar,” PR, 1949

“AcMiies and the Tortoise,” A, 1950-51. Reprinted in Problems of Anal-
ysis

“Definition, Presupposition, and Assertion,” PR, 1952. Reprinted in Prob-
lems of Analysis

“Phenomenalism,” in Science, Language and Human Rights (Proceed-
ings of American Philosophical Association, Eastern Division), 1952.
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Analysis

‘^ying and Disbelieving,” A, 1952-53. Reprinted in Problems of Analysis,
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“Why Cannot an Effect Precede its Cause?,” A, 1955-56
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Blumberg, A. E. and Feigl, H., “Logical Positivism, a New^ Movement in
European Philosophy,” JP, 1931

Boas, G. and Blumberg, A. E., “Some Remarks in Defense of the' Operational
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Bohneit, H. G., “The Semiotic Status of Commands,” PS, 1945
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1950- Reprinted in Eiton, W., Aesthetics and Language
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gffWh waite. R. B. {continued)

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Buckley, F. B., “Analysis of ‘X Could Have Acted Othervrise,’ ” PSi, 1956
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Butler, R. J., “The Scaffolding of Russell’s Theory of Descriptions,” PR, 1954
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Capek, M., “The Development of Reichenbach’s Epistemology,” RM, 1957-58
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■:

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SS'‘n!anmett> M. (continued)

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[ 407 ]

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Fener, L. S., “Mechanism, Physicalism and the Unity of Science,” PPR, 1948-49
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W. B. {continued)

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[4111

'gUMography of Logical Positivism
IML E. W. (continued)

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Harrison, J. {continued)

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O’Connor, B. J. {continued)

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mS:

■■■ ^
• £

tii

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Rudner, R-, “Formal and Non-Formal,” PS, 1949

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[ ] Bibliography of Logical Positivism

RmseH B. {continued}

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Syntkese,

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Index

Ackennas, W., 135
Adjuciewicz, K., 6, 7, 241
Analogy, 229, 373; arguments from,
176, 177 ,

Analysis, 5, 324; critical, 363; logical,

7, 76, 124 n., 133, 145, 169, 1/7,
293, 317; logical, and philosophi-
cal problems, 8; logical, and phi-
losophy, 77; logical, as business
of philosophy, 47; philosophical,
23, 28; see also Definition
Antinoiiues, logical, 139
Aquinas, 134

Aristotle, 333, 334, 368, 369
Arithmetic, 200, 341; also Logic
St Augustine, 218, 346, 347, 360, 362
Austin, J. L., 9, 28
Avenarius, R., 4, 85, 86, 291
Axiom(s), 346; and philosophy, 330;
of geometry, 360; doubtful, 31;
see also Geometry, Logic, Mathe-
matics

Axiomatization, 136
Ayer, A. L, 6, 8. 110 n., 112 n., 114,
115, 116, 123 n., 124 n.

Bar-Hillel, Y., 8

Behavior, 21, 189, 294, 296, 304, 305,
306, 307, 312; meaningful, 181,
182; moral, 263; of groups 301,
316; physical, 181; understand-
able, 182: see also Psychology
Behaviorism, 181, 286, 296, 297, 299,
300, 316; social, 296, 301, 303,
308-310, 313, 315-317
Behmann, H-, 135
Benjamin, A. C., 108 n.

Bentham, 4
Bergson, 80

Berkeley, 16, 17, 97, 368
Bemays, P., 135

h 4.

7, 8, 13, 18,

20,

21,

25,

26, 27, 28,

107

n.,

1 17.

n9, 120,

122

n..

125

n., 128 n..

133

Black, M., 8, 165 n., 199n.

Blake, William, 365
Blondiot, R., 91
Blumberg, A. E., 106 n.

Bolzmann, L., 4
Boole, G., 134

Bradley, F, H., 32, 41, 42, 43, 46, a74
Braiihwaite, R. B., 6
Brentanc, F-, 4
Bridgman, P. W., 120 n.

Calvinism, 310, 311
Cantor, G., 32, 359, 364
Capitalism, 310, 311

22, 24,
no n..

147 n.. 165 n.. 199 n., 201, 202 n.,
203. 204, 205, 206, 207, 208, 209,
210, 213 n., 231, 233 n., 235,
236, 237, 238, 282, 290, 298, 324
Causation, 242
Chisholm, B.. M., 120 n,

Church, A., 8, 116
Chwisiek, L., 6. 135
Ciccotti. E., 215 n.

Cognition, 219. 222, 223, 227; or toe
good, 250

Coleridge, S. T., 367
Coilingwood, R. G., 327, 328, 329
Common-sense, 8, 101, 110 n., 356
Comte, A., 4, 83

Concepts, 13, 17, 24, 133, 145, 146,
232. 233, 248, 288, 334-336, 338,
341, 342, 376; and the given, 144;
clarification of, 283; dispositional,
186, 187, 197; kinematic, 186;
limiting, 286; logical, powers of,
333; of the good, 250, 251, 253,
255 256, 261; of mathematics,

Index

[448 ]

Concepts {continued}

135; of the new logic, 141; of
physics, 182, 184, 186; of science,
143; physical, 167, 181-183, 186;
psychoio^cal, 167, 185, 189, 190,
197; socioiogicai, 311
Conditional, coimterfactuai, 120; ma-
terial, 119, 120

Confirmability, 111 n., 114, 146
Confirmation' 221-223, 225, 226
Connective, logical, meaning of, 142
ConsdoHsness, 258, 306; content of,
98, 103, 177, 218; date of, 94, 98,
99

Constructs, empirical, 22, 121; hypo-
thetical, 197; theoretical, 122 n.
Contradiction, iaw^ of. 153, 155; truth,
as absence of, 214

Convention(s), 236, 237, 238. 240;
and basic proposiiions, 235; lin-
guistic, 238
Copernicus, 167
Cornelius, H., 107 n.

Couturat, L., 32

Darwin, 167
Darwinism, 377

Data, 110; observ'aiional, 112, 211;

primitive, 237; see also Protocols
Deduction, 115. 136. 156, 157, 305,
330, 360, 373

Definition(s), 322, 323, 365; actual,
322, 323; as a system of philos-
ophy, 322; implicit, 361; nominal,
322; of a word, 323; ostensive,
25; see also Analysis
DeMorgan, A., 134, 139
Descartes, 54. 74, 98, 99. 209, 362,
377, 379, 380

Description(s), common-sense. 15;

physicalistic, 295; theory of, 36
Determinism, 26, 353
Dilthey, W., 79

Disagreement, ethical, 279; in belief,

277, 278, 279; in interest, 277,

278, 279
Driesch, H., 290
Duhem, P., 4, 208

Economy, principle of, 216, 217, 218,
231

Einstein, A., 4, 58, 59, 89, 139, 151,
161, 174, 200, 360, 376, 379
Eieatics, the, 83

Emotive theory of ethics, 22 264

fi.; see also Ethics
Empathy, 296, 298, 299
Empiricism, 8, 31, 106, 107, 108, 143,
149, 150, 209; see also Experi-
ence

Enriques, F., 44
Epicurus, 4

Epimenides, paradox of, 41
Esthetics, 58

Ethics, 6, 17, 21, 22, 57, 261, 267,
268, 277, 278, 281, 304, 305-309;
and knowledge, 247, 248; and
life, 258; and psychology, 280;
and truth, 247; as factual science,
258; as normative science, 256,
259; as science, 247; as part of
psychology', 65; concept of, 252;
emotive theory of, 22, 23; facts
of, 252; imperative theory of, 22;
method of. 263: philosophical,
253; questions of, 247, 248, 259,
263, 264; task of, 250, 251, 256,
261; theological, 252
Euclid, 31. 330, 366
Evil, 252. 254. 255, 258/ 259, 260,
261

Existence, 36, 73 fi., 96, 106, 332;

of the external w^orld, 85
Experience (s). 11. 18, 20, 21, 26, .86,
108, 109, 144, 145, 148, 150,

151, 161, 194, 213. 215, 219,

223, 225, 229, 230, 234, 240,

242, 248; and mathematical and
logical propositions, 149, 152;
and science, 221; atomic, 204;
immediate, 204: moral, 240
Explanation, 260; historical, 328

Facts, 25, 115 n., 151, 159, 209, 210,
214, 225, 226, 228, 229, 235,

238’, 24 i’ 257,’ 258* 269,’ 285’,

324, 329, 348, 355, 357; abso-
lutely simple, 11; and the laws
of excluded middle and contra-
diction, 153; and simples, 42, 43;
and statements, 155; atomic, 11;
empirical, 212, 278; knowledge

Index

Facts (continued)

of, 152; natural, 22; norms, ^ as
expression of, 255; of ethics,
252; of perception, 218; pri-
maiy, 212; relation between prop-
ositioE and, 242; see also Judg-
ments, Propositions, Sentences,
Statements

Faisifiabiiity 113, 114, 127, 128
Falsification, 229
Fatalism, 355, 368

Feigl, H., 3, 7, 8, 106 n., 120 n., 122
123 n., 128 n., 146, 197, 198
Fermat, P., 72
Feuerbach, L., 4
Fichte, 80
Field, G. C., 267
Flew, A., 239 n.

Form, logical, and knowledge, 55
Formal mode of speech, 25, 165, 237
Frank, P., 3, 6, 7, 107 n., 128 n., 287
Frege, G.. 4, 10, 32, 3 j, ^5, 54, i24 n»,
134, 135, 140, 208, 282, 356, 358,
359, 361, 363, 378
Freud, S., 168

Galileo, 376

Geometry, axioms of, 360; non-Eu-
ciidean, 32; see also Logic,
Mathematics

Gestalt psychology, 169, 237, 238
God, 16, 66, 94, 239, 240, 252, 253,
300

Godel, K., 2, 7, 8, 359
Goethe, 367

Good, 248-256, 258-260, 264-271,
274, 275, 280, 281; as indefin-
able, 251; cognition of, 250; con-
cept of the, 250-256, 262; con-
tent of, 253; definition of, 249;
formal characteristics of the,
252; material characteristics of,
253; scientific knowledge of, 261;
see also Ethics

Goodman, N., 7, 8, 26, 27, 117, 120 n.
Graphology, 185, 186, 188, 189, 190

[ 449 ]

Hegel, 32, 73, 75, 80, 134, 143
Heidegger, M., 16, 69 n., 71, 75, 80,
200

Heisenberg, W., 376
Heimholz, H., 4

Hempel, C. G., 5, 7, 8, 120 n., 128 n.,
229, 230 m, 231, 234, 237
Heraclitus, 374

Hilbert, D., 4, 135, 360, 361, 379
Hobbes, 265, 266, 267, 277
Hume, 4, 10, 11, 22, 31, 265, 266,

267, 367, 376
Hypostatization, 264

Hypothesis, 14, 15, 18, 20, 21, 220,
222, 223, 226, 227, 329, 331;
and scientific theory, 214

Idea(s), 332-336, 338-340, 343, 344;
abstract, 340, 341, 343; arith-
metical, 337; concrete, 340, 343;
general, 347; logical power of,
332-335, 337, 340, 344; Platonic,

268, 280

Idealism, 9, 15, 41, 85
Imperative(s), 22, 278, 279; cate-
gorical. 268; see also Ethics
Induction, 169, 220, 298, 299, 329,
345

infinity, 359

introspection, 191, 192, 194, 262,
380; see also Behaviorism, Con-
sciousness

Intuition, 188, 239; and knowledge,
102; logical, 359; moral, 21
Intuitionism, ethical, 23

James, W., 37, 228
Jevons, W. S., 292
Joergensen, J., 5, 7
Judgment(s), 210, 211, 213, 261, 304;
analytic, 224; moral, 22, 23, 254,
255, 258, 261, 262, 267, 268,
269, 270, 277, 278, 279, 280,
304, 305; of observation, 222
von Juhos, B., 242
Jurisnnidence, 205. 207, 309

[ 450 ]

Kant {continued)

253, 256, 259, 346, 34S, 360, 376,
3S0

Kaplan, A., 122 n.

Keisen, H., 307 n., 308 n.

Kepler, 360

Knowledge, 10, 56, 144, 148, 151,
171, 210, 212, 220, 221, 227,
334, 340, 343; a priori, 152; and
ethics, 247, 248; and positivism,
90; and re^ty, 226; as intuition,
102; as sensation, 102; basis of,
20, 213, 216, 222, 223, 226; cer-
tainty of human, 209; empirical,
278, 279; intersubjective, 211;
limitation of human, 72, 73;
metaphysical, 72; non-analytic,
108; of facts, 152; of other
minds, 177; of physiolog\% 175;
origin of, 221; scientific, 17, 125,
284; scientific, of the good, 261;
systems of, 219, 222; theor>'' of,
133, 136, 209, 292, 293; thi^-
ing and, 149; see also Empiri-
cism, Rationalism
Kotarbinskv, T., 6, 7
Kraft, V., 3, 7
Kraus, O., 310, 311
fCronecker, L., 25

Laas, E., 85
Langford, C. H., 120 n.

Language, 19, 21, 23, 24, 26, 27, 55,
“■llO n., 116, 117, 152, 157, 167,
177, 179, 205, 214, 219, 237, 238,
241, 271, 285, 289, 295, 323, 340,
342’ 343, 350, 354, 358, 362-364,
366, 372. 374; and contemporary
British philosophy, 5; and type
confusion, 75; constituents, 61;
current uses of, 7; empiricist,
116-118, 120-123, 128 n.; games,
27; ideal, 199; influence on phi-
losophy, 38; intersubjective, 205,
206; logical, construction of, 45;
logical syntax of, 6; of everyday
life, 287; of physics, 287; of sci-
ence, 28, 199, 200, 202, 203;
ordinary use of, 9; phenomenalis-
tic, 201; protocol, 165, 182, 188,
201, 202, 205-207; structure of,

Index

24; subject-predicate, 39; system,
24, 166, 235; see also Meaning
Lazerowitz, M-, 8

Leibniz, 4, 32, 44, 54, 134, 135, 137,
139, 380

Lesnievsky, S., 6, 135
Leverrier, U. J. J., 151, 160
Lewin, K., 284
Lewis, C. L, 120 n.

Lichtenberg, G. C., 350
Xx)ckc 19

Logic,’ 8, 22, 74, 96, 114, 117, 134,

150, 152, 236, 282, 284-286, 317,
322, 324, 358, 372, 376; and
mathematics, 134, 307; and meta-
physics, 60, 143: and numbers,
135; and symbolic method, 136;
applied, 134; as method of
philosophizing, 153 f., laws of,

151, 153; mathematics as branch

of, 140, 143; natural, 366: of re-
lations, 137; of science. 24; phi-
iosopm' and, 24, 134, 364. 376;
propositions of, 158; lautoiogical
character of, 141, 142, 143;

three-valued, 353; traditional,
133, 134; see also Empiricism,
Rationalism

Lukasiewicz, I., 6. 135, 353'

Mach, E., 4, 9, 85, 86, 139, 174, 20S,
282

Malcolm, N., 8
Malebranche, 380
Maithus, 312
Mannoury, G., 6
Marc-Wogau, K.. "

Marx, 4, 167, 312
Marxism, 7, 9, 306. 308, 309, 315
Material mode of sneech. 25. 165 fi..
257 g-

Materialism, 324, 345
Mathematics, 135, 150, 158, 159, 282,
284, 285, 286, 322, 370. 377; and
logic, 134, 307; and reality, 360:
as branch of logic. 140, 143:
foundations of, 32, 135; laws of,
151; propositions of, 158; sen-
tences of, as analytic, 143; sen-
tences of, as tautologies, 142; un-
decidabie questions in, 359; see

Index

Mathematics {continued}

aha Empiricisin, Logic, Ration-
alism

Matter, 36; as logical construction,
37; history of, 49
McTaggart, J. E. M-, 16
Maxwell,, G-, 12S n.

Maxwell, J. C, 33, 151
Meaning, 15, 19, 122, 225, 226, 228,
231, 272, 293, 321, 323-325; and
name, 249; and pseudo problems,
56; cognitive, 116, 117, 123; com-
municability of, 95; criterion of,
14, 108, 115 n., 116 ff.; emotive,
10, 273-277, 280, 291; empirical,
110, 111, 113, 122; of ethical
terms, 271; of a logical connec-
tive, 142; of a philosophic ques-
tion, 86; of a proposition, 87,
90 ff., 106; of a word, 62 tt.; os-
tensive, 57; verifiable, 95; see
also Language, Metaphysics
Menger, C., 4
Menger, K., 3

Metaphysics, 8, 9, 10, 11, 14, 17, 72,
83, 159, 166, 283-286, 291, 292,
299, 301, 304, 305, 309, 316, 317;
and logic, 60, 143; and physics,
174; and psychology, 174; and
science, 174; as attitude towards
life, 78 E.; as substitute for art,
80; Berkeleyan, 85; elimination
of, 145, 300; error of, 57; his-
torical role of, 78; idealistic, 85,
86, 290; meaning of words, 65;
solipsistic, 85

Method, axiomatic, 360, 361, 379; em-
pirical, 267, 268, 277, 278, 279,
280; mtuitive, 170, 171, 182, 191:
of ethics, 263; of philosophical
reasoning, 343; of philosophy,
23; rational, 170, 188; scientific,
8, 200, 267, 268, 283, 305, 308,
317, 327; see also Empiricism,
Rationalism, Science
Min, L S, 4, 31, 32, 97, 143, 257, 258
Mind(s), 15, 16, 170, 174, 191, 213,
234, 239, 332, 345, 347, 348; and
space-time, 49; knowledge of
other, 177; puzzle of other, re-

i J

solved, 206; see abo Behavior,
Consciousness, Introspection
von Mises, R., 5
Monism, 40, 45

Moore, G. E., 3, 5, 8, 28, 32, 243,
250, 266 n-, 268, 280, 321, 345,
368, 375

Morris, C, W., 6
Mulier-Lyer figure, 4
Mysticism, 5

Nagel, E., 6, 7

Nature, 151, 307, 328, 380; laws of
160-161

Neo-Hegelianism, 9
Neo-Kantianism, 9
INfess Ak. 5 7

Neurath" o!, 3, 4, 5, 6, 7, 20, 206, 207,
211, 214, 229, 230, 231, 237, 286,
300, 314 n., 317 n.

Newton, 135, 139, 160, 161, 348, 360,
380

Nietzsche, 80, 168, 350, 374
Norm(s), 255, 256, 257, 259, 261; as
expression of fact, 255; ethical,
and life, 258; moral, 255, 262;
system of, 261; theory of, 260; ul-
timate, 258; see also Ethics
Nothing, the (‘"das Nichtes”)* 16,
69 fi.

du Noiiy, Lecomte, 109
Number(s), and logic, 135; natural,
359; see also Mathematics

Objectivity, 247

Observation (s), 14, 18, 20, 21, 109,
115 n., 147-153, 155. 160, 161,
215, 216, 220, 228, 230, 231, 233,
236; and theory in physics, 160;
data of, 211; facts of immediate,
215; judgments of, 222, language,
197; predicates, 117-119, 121,
122; sentences, 63, 76, 110, 111,
113-116, 122, 123, 146; state-
ments, 200, 219, 221, 222, 223,
225, 226, 283, 285, 287, 289, 290,
300; see also Data, Facts
Occam’s razor, 34
Ogden, C, K., 73
Ontology, 26
Oppenheim, P., 120 n.

[452 ]

Oppenheimer, F., 284 n.

Pap, A., ilO B-. il4 n., 124 n.
Paradoxfes), 333, 334, 340, 349, 351;
logical, 330, 333, 336; of Achilles
and the tortoise, 351, 352
Fhscal, 366
Pasch, M., 4
Paul, G. A., 239 n.

Pavlov, I., 298

Peano, G-, 4, 10, 32, 134, 135
Pears, D., 9

Perception, 17, 110 n., 117, 144, 205,
226, 252, 287, 289; centers, 292;
and experimental propositions,
99; external, 296; internal, 296;
organic, 290, 297, 298; sensory.

Perry, " r. B., 265
Petzail, A., 5, 7, 106 n.
Phenomenology, 1 68
Philosophy. 17, 23, 24, 26, 177, 204,
208, 282, 283, 293, 294, 325, 336,
364, 365, 374-376, 379, 380; ana-
lytical, 3: and empirical sciences,
133: and logic, 24, 134, 364, 376;
and posmlaies, 330; as a system
of dennitions, 321, 322; contrast-
ed with science, 56-57, 34 d: mean-
ing of, 57; method of, 346. 367:
nature of, 346, 367; not a science,
56 g.; scientific, 77; task of, 356
Physicaiism, 21, 27, 166, 167, 175, 182,
185. 194, 197, 198, 200, 202, 208,
282’ 286-292, 296, 297, 299, 305,
309, 317; language of, 287, 290;
statements of, 290; unified lan-
guage of, 286, 308, 317; see also
Behaviorism

Physicalization, 182, 184, 186-189: in
graphology, 185; of psychological
concepts, 190

Physics, 147, 148, 169, 172, 197; and
metaphysics, 174; and science,
166; concepts of, 182, 186, 197;
psychology as part of, 168, 197;
theory^ and observ’ation in, 160
Picasso, P., 379
Fieri, M., 4
Planck, M., 90

Plato, 83, 134, 342, 346, 347, 367, 369,
375

Index

Pluralism, 32, 40, 45
Poincare, H., 4, 159, 174, 208, 282
Popper, K., 6, 7, 13, 14, 113 n., 120 n.,
213 n., 229 n,, 235, 236
Popper-Lynkaeus, 4
Positivism, 5, 8, 9, 83, 106; and the
externa! world, 85; and knowl-
edge, 90; and reality, 97; logical,
3-28 passim, 106, 359; methodo-
logical, 144, 206, 207; see also
Empiricism, Vienna Circie
Postulates, and philosophy, 330
Pragmatism, 27, 37
Price, H. H-, 232, 242
Probability, 232, 233
Propositions, 15, 19, 23, 24, 27, 87 £,
107, 159, 229-232, 236, 238. 241,
285, 317, 330-333, 336-33S, 34G-
343; and words, 317; basic, 229,
230, 235, 236, 237, 23S. 243;
concrete, 235; criterion of iniih
and faisitv of, S7; emnirical. SI',,
90 fi., 106, 228, 233,* 234, 236.
239, 243; existential, and percep-
tions, 99; existential, logical form
of, 98; factual, 10, 237': hrst-or-
der, 242; formal 10: logical pow-
ers of, 331, 332, 333, 337; of sci-
ence, 19, 23; philosophical. 25, 24.
329; protocol, 230, -231, 233. 234,
235, 236, 237; pseudo-factual.
237, 238; pseudo-syniacticaL 238:
relation between fact and. 242;
significant, 10; singular, 228; 229,
236; syntactical 237, 238; system
of empirical 231; universal 228.
229; see also Facts. jTiagmenis..
Sentences, Statements
Protocols), 202, 203, 205, 206. 20“ .
221, 226, 231. 236; of science.
226; see also Statements, Sen-
tences

Proust, M., 350, 367
Pseudo-Statements, 61, 64, 67-68; and
logical mistakes, 73; metaphysi-
cal, 69

Psychoanalysis, 306
Psychology^ 58, 165 ff.. 172, 263, 267,
296, 300, 306, 323, 325; and
ethics, 280; and metaphysics, 174;
as part of physics, 168, 197; con-
cepts of, 189, 198; ethics, as pan

Fs?cbology {continued)

■ of 263; Gestalt, 169; introspec-
ti¥e, 191; intuitive, ISl, 182, 184;

occurrent properties^ of, 186; of
sensution, 238; scientific, 198; sen-
tences of, 183; also Beliavior-
ism, Physicalism

- Quality, experience of, 93;^ primary,
19; primary and secondary, 297;
statements about, 297
Quine, W. V., 6, 7, 8, 26, 27, 28

Ramsey, F. P., 6, 19, 21, 23, 28, 135,
241

Rationalism, 150, 159 ff., 310; see
also Knowledge

Realism, 15, 21, 41, 107: and the ex-
ternal world, 85; metaphysical,
105

Reality, 23, 96, 105, 148, 151, 211,
214, 225, 228, 230, 240, 241,
263, 292, 295; absolute, 104;
agreement with, 215, 229, 234;
and mathematics, 360; and sen-
sations, 98; and thinking, 159;
knowledge of, 225, 226; of the
external world, 85, 86, 91, 95 ff.,
100; positivism and the question
of, 84 ff.. 97; transcendenh 101,
102, 105

Reductio ad absurdum, 330, 335, 336,
337, 338, 343, 369, 370 ft., 374
Reichenbach, H., 5, 6, 120 n., 122 n.
Reininger, R., 286

Reiation(s), and monism, 40; and
pluralism, 40; and subject-predi-
cate logic, 39; internal and ex-
ternal, 42 ff.; reality of, 32, 46;
theory' of, 137; transitive and
symmetrical, 34
Richards, L A., 273
Rickert, H., 303
Riemann, B., 4
Rilke, R. M., 380

RusseE, B., 3, 4, 8, 10, 11, 12, 17, 24,
26, 27, 54, 98, 108 n., 110 n.,
Ill n., 113 n., 124 n., 135, 138,
139, 140, 208, 321 n.

Ryle, G., 6, 8, 9, 27, 367, 373
Rynin, D., 128 n.

Scepticism, 31

Scheffler, L, 128 m, 129 n., 378
Schelling, 80, 134
Schiipp, P. A., 198
Schlick, M*, 3, 5, 6, 20, 21, 22, 24,
Him, 133 m, 221 m, 286
Scholasticism 325
Schoiz, H., 6, 7

Schopenhauer, 263, 347, 348, 349
Schroder, E., 4, 135, 208
Science(s), 17, 21, 25, 185, 208-212,
^20, 222, 223, 226, 227, 234,

247, 249, 263, 285-287, 291, 293,
296, 298, 301, 303, 305, 317,

332, 358, 364, 365, 376, 377,

380; and experience, 221; and

physics, 166; as data of philoso-
phy, 46; concepts of, 143, 187;
concepts of, unified, 287; con-
trasted with philosophy, 56, 57,
345: dennition of, 56; ethics, as
factual, 258; language of, 24;
logic of, 24; logical starting point
of, 211; moral, 294, 295, 296,
298, 308; normative, 256, 258,
260; social, 21; statements of,
19, 20, 23, 212, 213, 226; system
of, 210, 219; unified, 143, 166,
200. 201, 204, 207, 208, 282-287,
281, 293, 294, 296, 297, 305-308,
316, 317; unity of, 146
Scriven, M., 128 n., 146,- 197
Segerstedt, T. T., 7
Sellars, W., 221 n.

Semantics, 6, 20, 177; see also Lan-
guage, Meaning

Sensation(s), 17, 107, 110 m, 117,
238, 241, 259, 323; and knowl-
edge, 102; and reality, 98; Gestalt
theory 238; psychology of,
238

Sense-data, 13, 17, 18, 229, 236, 242
Sense-impressions, 90, 346
Sense-perception (s), 148, 179, 290
Sentences, 24, 25, 109, 115 m, 117,
122, 124, 127, 128 n., 129, 137,
142, 166, 167, 171-74, 176, 179,
180, 192, 203, 204-208, 211, 224,
230, 231, 234, 241, 336, 337;
about other minds, 170, 174, 175,
176, 192, 197; about one’s own
mind, 170, 192, 194, 195; ana-

Index

[454]

Sentences (continued)

ivtic. 111, 115; atomic, 199, dy-
jiamic use of, 271; of
matics, as

tion, 174; physical, 175, 182, 194,
195; observation, 63, /o,

in 113-116, 122, 123, 166, 171,
175, 185, 191, 194, 195, 199,
-100 202-205, 207; psychological,
182’, 183, 190, 193, 197; reduc-
tion, 120, 121, 128; tautological,
142- 143; see also Facts, Proposi-
tions, Protocols, Statements
Significance, see Meaning

Simples, denned, 44 ^

Simultaneity, ^89 It., 94, :>19

S’girt'W 300 301, 3W.

307-309, 312, 316, 317; empmcal,
306, 308, 309, 315, 316, 317;
physicaiistic, 301

Socrates, 342, 343 , . i i

Solipsism, 13, 18; methoaologicai,

206, 207, 290, 293; theory or
multiple, 19
Somban, W., 296
Suace, 48, 49. 58. 151, 166, 3^9
Space-Time, 48, 49, 286; points, 19/,
235

IpinoS: S: .-4, 346, 366, 376, 380
Stace, W. T., 108 n., 115 n._^
Statement(s), 11, 13,

20 21, 27, 116, 12/, i28, 13/,
213, 214, 224, 234, 238, 286, 291-
293, 299, 316, 332, 365; about
qualities, 297; about reality, 91-
292; agreement of, 216; analytic,
27, "223-225: and concepts, 133;
and facts, 155; and their ori^n,
218; and value-judgments, 77;
basic, 216, 217; common-sense,
16; corrigibiiity of, 216; descrip-
tive, 22; elementary and com-
plex, 11; empirical, 18, 20, 21,
23, 122; ethical, 22, 278, 281;
formal, 23; impossibility of mean-
ingful metaphysical, 76; intro-
spective, 195, 196; kinds of mean-
ingful, 76; mathematical, as tau-
tnloeies. 158: meaningless, 284,

286, 317; metaphysical, 16; nor-
mative, 22; observation, 219-223,
225, 226, 283, 285, 287, 289, 290,
300, 307, 310; of physicaHsm,
290; of physics, 147; of science,

20, " 212 , 226; of unified science,
'>95; philosophical, 25, 26; physi-
20, 180, 290; physicaiistic,
293 296-298; protocol, 20, 209-
213, 216, 2X7, 219-221, 234, 237,
238, 290, 309; protocol, logical
and temporal priority of, 211;
psychological, 198; relational,
138; scientific, 16; semantic, 25;
significant, 12, 125; singular, 210;
synthetic, 27, 227; two kinds of,
154, 155; universal, 210, 222;

also Facts, Judgments, Propo-
sitions, Protocols, Sentences
Stebbing, L. S., 6
Stevenson, C. L., 8, 22
Strabo, 313
Strawson, P. F., 9, 23
Syntax, 26, 284, 292; logical, 24, 208;
unified, 284

System(s), 129, 231, 232, 234, 28.,
292, 317, 378, 384; Aristoteiian-
Scholastic of logic, 134; > axiom-
adzed uninterpreted, 121; ethical,
248, 256; formal, 359; Hegel’s,
143; h^TOtheiico-deductive. 121;
Konsdtution, 24; of definitions,
philosophy as, 32, 322; of empiri-
cal proposidons, 231; of knovvi-
edce, 219; of norms, 261; or
proposidons, 157; 01 science, 210,
'^12y 219, 233; philosophical,

346; physbal, 180, 291; physicai-
istic, 292; positivist and matenal-
isdc constitution, 144; specula-
tive, 376; symbolic, 199, theo-
retical, 122; also^ Logic,

Mathematics, Metaphysics, Sci-
ence

System-ianeuage, physicaiistic, 235,
237

Tabula rasa, 201
Tarski, A., 6, 7, 8, 20, 124
Tautology hes), 12, 76, 143, K5, Dc,
156, 159, 200, 202, 223, 228,

[ 455 ]

ituie*

TantDlogydes) 322-

7%9 2U, 292, 297, 3m,
defiiution of, 142; mathematical
^temeats as. 158; propositions
of logic as, 157; see also Logic,
Mathematics

?Sl“Sl,‘203,'?08, 307. 324, 32S.
■^^^2 333 351; demonstrative,

225; disposition, 1 18, 1 19, 120;
empirical, 118, 121 ; ethical, 22,
270 271, 281; significant, 128
Theology, 295, 297, 304, 316; see also
God, Metaphysics

Testability. 110; criterion, 114 115,

116, iiS* i24; see also Falsm-
abiiity, Veriliabiiity
Theory, 146, 214, 327, 335; and hy-
pothesis, 214; and observation in
physics, 160; scientific, 214;
sense-datum, 357; see also Sci-
ence ^ ,

Thought, 156, 211, 323, 374; delusions
of, 149, 150

rune, 16, 48, 49, 58, 89, 151, 166,
211, 289, 325, 347-351,361, 362,
369; see also Space-Time
Transformation, tautological. 158, 159
Translatability, 116, 122, 128 n., 167,
190; criterion, 117, 118, 121, 128
Truth, 213, 218, 225, 230, 231, 232,
238, 241, 263, 280, 327, 340, 353,
354, 355, 376, 377; as absence of
contradiction, 214; as mutual
agreement of statements, 214;
coherence theory of, 20, 214,
215, 216, 231, 232, 233, 242; cor-
respondence theor>- of, 21, 214;
criterion of, 213, 215-216; ethics
and, 247; formal, 22, 215, 223-
224; nature of, 214; nature of
arithmetical, 358; necessary, 352;
of empirical proposition, 234; of
statements, 24; philosophic, 283;
semanticai definition of, 124 n,
Type(s), logical, 40 ff., 333 fi., 336,
337, 339; logical and meaning
of words, 41 fi.; theory of, 136,
140, 359; violation of rules of
theory of, 75; see also Paradox

Universais, 38, 39

Vagueness, 264
Vaihinger, H., 85
Vailati, G-, 4

Validity, 142, 152, 210, 223, 224, 226,
229, 231

Vaine(s), 240, 257, 258, 260, 307,
323; post-Kantian philosophy of,
263; world of, 14, 22; also
Ethics

Verifiability, 111 n., 114, 127, 128,
146; criterion of. 111 n., 113,
127; in principle, 88, 111; see
also Verification

Verification, 13 S., 21, 56, 94, 106,
201, 204, 212, 221, 222, 223,
225, 235, 236, 242, 291; method
of, 13, 87 g.

Vienna Circle, 3-9, 15, 21, 22, 24, 110,
207, 208, 282, 283, 286, 291

Waismann, F., 3, 5, 6, 7, 28
Watson, J. B., 298
Weber, M., 310, 311
W’edberg, A., 7
Weierstrass, K* T. W., 32
Werkmeister, W. H., 112 n.
Whitehead. A. N., 4, 12, 33, 34, 36,
135, 140

W’isdom, 342, 343
Wisdom, J., 6, 8, 9, 243
Wittgenstein, L., 3, 4, 5, 7, 8, 11, 12,
13, 15, 17, 23, 24, 25, 27, 28,
54, 76, 135, 146, 208, 214, 282,
284, 285, 321, 325, 326, 356, 373,
374, 375, 380

Word(s), and propositions, 317; defi-
nition of, 323; dynamic use of,
272, 273; meaning of, 62 ff-,
meaningless, 145; meaningless se-
quences of and natural language,
67; see also Propositions, Sen-
tences

von Wright, G. H., 7

Zeno, 351, 368
Ziisei, E,, 3, 241 n.

I2.3fi7